{"kind": "plan", "major": "18", "item": {"slug": "bitmapand", "name": "BitmapAnd", "name_zh": "BitmapAnd", "category": "\u4f4d\u56fe", "summary": "\u5bf9\u5404\u5b50\u8ba1\u5212\u4ea7\u751f\u7684\u4f4d\u56fe\u6c42\u4ea4\u96c6\u3002", "aliases": ["BitmapAnd", "T_BitmapAnd"], "content_hash": "1dd861e5dc07c02d945e970b5cc29ee1db8d045ea33c5999f3e87b542290b740", "versions": {"10": {"facts": [{"label": "\u6838\u5fc3\u8282\u70b9\u6807\u7b7e", "value": "T_BitmapAnd"}, {"label": "\u7ed3\u6784\u5316 EXPLAIN \u8282\u70b9\u7c7b\u578b", "value": "BitmapAnd"}, {"label": "\u8f93\u5165", "value": "\u4ea7\u751f\u4f4d\u56fe\u7684\u5b50\u8ba1\u5212"}, {"label": "\u8f93\u51fa", "value": "\u5143\u7ec4\u4f4d\u7f6e\u4f4d\u56fe\uff0c\u4e0d\u662f\u5143\u7ec4\u6d41"}, {"label": "\u6267\u884c\u5668\u521d\u59cb\u5316\u51fd\u6570", "value": "ExecInitBitmapAnd"}, {"label": "\u5185\u5b58\u673a\u5236", "value": "unclassified"}], "memory": {"evidence": [{"url": "https://ftp.postgresql.org/pub/source/v10.23/postgresql-10.23.tar.bz2", "path": "src/backend/executor/nodeBitmapAnd.c", "label": "src/backend/executor/nodeBitmapAnd.c", "sha256": "7c6494770b448c0beb9991dc604adec47c5362ccc301b10df00f0ff5b6b53d7c", "archive_sha256": "94a4b2528372458e5662c18d406629266667c437198160a18cdfd2c4a4d6eee9"}], "mechanism": "unclassified", "description": "\u672c\u6b21\u62bd\u53d6\u4e0d\u4e3a\u6b64\u8282\u70b9\u8bbe\u5b9a\u7edf\u4e00\u7684\u5185\u5b58\u4e0a\u9650\u6216\u843d\u76d8\u7b56\u7565\u3002\u8bf7\u67e5\u770b\u540c\u4e00\u6784\u5efa\u7684\u5b9e\u73b0\u3001\u76f8\u5173\u8868\u8fbe\u5f0f\u6216\u63d0\u4f9b\u65b9\u3002", "source_notes": []}, "tables": [{"key": "explain-labels", "rows": [{"label": "BitmapAnd", "identity": "BitmapAnd"}], "title": "\u672c\u6784\u5efa\u4e2d\u7684 EXPLAIN \u6807\u7b7e", "columns": [{"key": "label", "label": "\u6587\u672c\u683c\u5f0f\u6807\u7b7e"}, {"key": "identity", "label": "\u7ed3\u6784\u5316\u8282\u70b9\u6807\u8bc6"}]}], 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"https://pg.center/docs/10/using-explain.html#USING-EXPLAIN-CAVEATS", "path": "using-explain.html", "label": "PostgreSQL 10.23 \u00b7 using-explain", "sha256": "a4b4304aedb0a2da0145cc7c35b03b319a5c7ee3df35a8ef84ab6d3a610f98f3", "language": "en", "original_url": "/docs/10/using-explain.html#USING-EXPLAIN-CAVEATS"}, {"url": "https://pg.center/docs/10/using-explain.html#USING-EXPLAIN-BASICS", "path": "using-explain.html", "label": "PostgreSQL 10.23 \u00b7 using-explain", "sha256": "a4b4304aedb0a2da0145cc7c35b03b319a5c7ee3df35a8ef84ab6d3a610f98f3", "language": "en", "original_url": "/docs/10/using-explain.html#USING-EXPLAIN-BASICS"}, {"url": "https://pg.center/docs/10/using-explain.html#USING-EXPLAIN-ANALYZE", "path": "using-explain.html", "label": "PostgreSQL 10.23 \u00b7 using-explain", "sha256": "a4b4304aedb0a2da0145cc7c35b03b319a5c7ee3df35a8ef84ab6d3a610f98f3", "language": "en", "original_url": "/docs/10/using-explain.html#USING-EXPLAIN-ANALYZE"}], "node_tag": "T_BitmapAnd", "sections": [{"title": "EXPLAIN \u540d\u79f0\u4e0e\u5c5e\u6027", "paragraphs": ["\u7ed3\u6784\u5316\u683c\u5f0f\u4f7f\u7528\u4e0a\u8ff0 Node Type\u3002\u6587\u672c\u683c\u5f0f\u540d\u79f0\u8fd8\u53ef\u80fd\u5305\u542b\u64cd\u4f5c\u3001\u7b56\u7565\u3001\u8fde\u63a5\u7c7b\u578b\u3001\u626b\u63cf\u65b9\u5411\u6216\u805a\u5408\u9636\u6bb5\u5c5e\u6027\u3002", "\u6b64\u6e90\u7801\u8bb0\u5f55\u7684\u6587\u672c\u540d\u79f0\uff1aBitmapAnd.", "\u5e76\u884c\u611f\u77e5\u4e0e\u5e76\u884c\u5b89\u5168\u662f\u4e0d\u540c\u7684\u8ba1\u5212\u5c5e\u6027\u3002\u5728\u5e76\u884c\u5de5\u4f5c\u8fdb\u7a0b\u5185\u8fd0\u884c\u7684\u8282\u70b9\u4e0d\u4e00\u5b9a\u662f\u5e76\u884c\u611f\u77e5\u8282\u70b9\u3002"]}, {"title": "\u5185\u5b58\u4e0e\u4e34\u65f6\u5b58\u50a8", "paragraphs": ["\u672c\u6b21\u62bd\u53d6\u4e0d\u4e3a\u6b64\u8282\u70b9\u8bbe\u5b9a\u7edf\u4e00\u7684\u5185\u5b58\u4e0a\u9650\u6216\u843d\u76d8\u7b56\u7565\u3002\u8bf7\u67e5\u770b\u540c\u4e00\u6784\u5efa\u7684\u5b9e\u73b0\u3001\u76f8\u5173\u8868\u8fbe\u5f0f\u6216\u63d0\u4f9b\u65b9\u3002"]}, {"title": "\u5e76\u884c\u6267\u884c\u4e0e\u8fd0\u884c\u4fe1\u606f\u91c7\u96c6", "paragraphs": ["\u4ee5\u4e0b\u6e90\u7801\u56de\u8c03\u53ef\u4ee5\u534f\u8c03\u6267\u884c\u6216\u6536\u96c6\u5de5\u4f5c\u8fdb\u7a0b\u7684\u6d4b\u91cf\u6570\u636e\u3002\u56de\u8c03\u5b58\u5728\u4e0d\u4ee3\u8868\u8be5\u8282\u70b9\u666e\u904d\u652f\u6301\u5171\u4eab\u5e76\u884c\u626b\u63cf\u6216\u5171\u4eab\u72b6\u6001\u3002", "\u6b64\u6784\u5efa\u7684\u56de\u8c03\uff1anone extracted from this node implementation."]}, {"title": "\u540c\u7248\u672c\u624b\u518c\u8bf4\u660e", "paragraphs": ["\u7531\u4e8e\u5b9e\u73b0\u4e0a\u7684\u9650\u5236\uff0cBitmapAnd \u548c BitmapOr \u8282\u70b9\u62a5\u544a\u7684\u5b9e\u9645\u884c\u6570\u59cb\u7ec8\u4e3a\u96f6\u3002"]}, {"title": "\u672c\u7248\u624b\u518c\u4e2d\u7684\u793a\u4f8b", "blocks": [{"code": "EXPLAIN SELECT * FROM tenk1 WHERE unique1 < 100 AND unique2 > 9000;\n\n QUERY PLAN\n-------------------------------------------------------------------------------------\n Bitmap Heap Scan on tenk1 (cost=25.08..60.21 rows=10 width=244)\n Recheck Cond: ((unique1 < 100) AND (unique2 > 9000))\n -> BitmapAnd (cost=25.08..25.08 rows=10 width=0)\n -> Bitmap Index Scan on tenk1_unique1 (cost=0.00..5.04 rows=101 width=0)\n Index Cond: (unique1 < 100)\n -> Bitmap Index Scan on tenk1_unique2 (cost=0.00..19.78 rows=999 width=0)\n Index Cond: (unique2 > 9000)", "source": {"url": "/docs/10/using-explain.html#USING-EXPLAIN-BASICS", "path": "using-explain.html", "label": "PostgreSQL 10.23 \u00b7 using-explain", "sha256": "a4b4304aedb0a2da0145cc7c35b03b319a5c7ee3df35a8ef84ab6d3a610f98f3"}, "paragraphs": ["\u793a\u4f8b\u6458\u81ea PostgreSQL 10.23 \u624b\u518c\uff1b\u672c\u767e\u79d1\u672a\u5b9e\u9645\u6267\u884c\u6b64\u793a\u4f8b\u3002", "\u5982\u679c WHERE \u5f15\u7528\u7684\u591a\u4e2a\u5217\u4e0a\u5206\u522b\u5efa\u6709\u7d22\u5f15\uff0c\u89c4\u5212\u5668\u53ef\u80fd\u9009\u62e9\u7528 AND \u6216 OR \u7ec4\u5408\u8fd9\u4e9b\u7d22\u5f15\uff1a"]}, {"code": "EXPLAIN (ANALYZE, BUFFERS) SELECT * FROM tenk1 WHERE unique1 < 100 AND unique2 > 9000;\n\n QUERY PLAN\n---------------------------------------------------------------------------------------------------------------------------------\n Bitmap Heap Scan on tenk1 (cost=25.08..60.21 rows=10 width=244) (actual time=0.323..0.342 rows=10 loops=1)\n Recheck Cond: ((unique1 < 100) AND (unique2 > 9000))\n Buffers: shared hit=15\n -> BitmapAnd (cost=25.08..25.08 rows=10 width=0) (actual time=0.309..0.309 rows=0 loops=1)\n Buffers: shared hit=7\n -> Bitmap Index Scan on tenk1_unique1 (cost=0.00..5.04 rows=101 width=0) (actual time=0.043..0.043 rows=100 loops=1)\n Index Cond: (unique1 < 100)\n Buffers: shared hit=2\n -> Bitmap Index Scan on tenk1_unique2 (cost=0.00..19.78 rows=999 width=0) (actual time=0.227..0.227 rows=999 loops=1)\n Index Cond: (unique2 > 9000)\n Buffers: shared hit=5\n Planning time: 0.088 ms\n Execution time: 0.423 ms", "source": {"url": "/docs/10/using-explain.html#USING-EXPLAIN-ANALYZE", "path": "using-explain.html", "label": "PostgreSQL 10.23 \u00b7 using-explain", "sha256": "a4b4304aedb0a2da0145cc7c35b03b319a5c7ee3df35a8ef84ab6d3a610f98f3"}, "paragraphs": ["\u793a\u4f8b\u6458\u81ea PostgreSQL 10.23 \u624b\u518c\uff1b\u672c\u767e\u79d1\u672a\u5b9e\u9645\u6267\u884c\u6b64\u793a\u4f8b\u3002", "EXPLAIN \u7684 BUFFERS \u9009\u9879\u53ef\u4e0e ANALYZE \u914d\u5408\u4f7f\u7528\uff0c\u4ee5\u83b7\u53d6\u66f4\u591a\u8fd0\u884c\u65f6\u7edf\u8ba1\u4fe1\u606f\uff1a"]}]}, {"title": "\u6267\u884c\u5668\u5b9e\u73b0\u8bf4\u660e", "paragraphs": ["\u8bf4\u660e\uff1aBitmapAnd \u4e0d\u4f7f\u7528\u5de6\u53f3\u5b50\u6811\uff0c\u800c\u50cf Append \u4e00\u6837\u7ef4\u62a4\u5b50\u8ba1\u5212\u5217\u8868\u3002\u4e0d\u8fc7\u5176\u903b\u8f91\u6bd4 Append \u7b80\u5355\u5f97\u591a\uff0c\u56e0\u4e3a\u65e0\u9700\u5904\u7406\u6b63\u5411\u6216\u53cd\u5411\u6267\u884c\u3002", "BitmapAnd \u8ba1\u5212\u6ca1\u6709\u8868\u8fbe\u5f0f\u4e0a\u4e0b\u6587\uff0c\u56e0\u4e3a\u5b83\u4eec\u4ece\u4e0d\u8c03\u7528 ExecQual \u6216 ExecProject\uff0c\u4e5f\u4e0d\u9700\u8981\u5143\u7ec4\u69fd\u3002", "\u5bf9\u6bcf\u4e2a\u5f85\u6267\u884c\u8ba1\u5212\u8c03\u7528 ExecInitNode\uff0c\u5e76\u5c06\u7ed3\u679c\u4fdd\u5b58\u5230 bitmapplanstates \u6570\u7ec4\u3002", "\u5982\u679c\u5728\u4efb\u4f55\u9636\u6bb5\u5f97\u5230\u5b8c\u5168\u4e3a\u7a7a\u7684\u4f4d\u56fe\uff0c\u5c31\u53ef\u4ee5\u76f4\u63a5\u9000\u51fa\uff0c\u65e0\u9700\u6267\u884c\u5269\u4f59\u5b50\u8ba1\u5212\uff0c\u56e0\u4e3a\u518d\u8fdb\u884c AND \u8fd0\u7b97\u4e5f\u4e0d\u4f1a\u6539\u53d8\u7ed3\u679c\u3002\uff08\u6ce8\u610f\uff1aindxpath.c \u6309\u9009\u62e9\u7387\u5bf9\u5b50\u8ba1\u5212\u6392\u5e8f\uff0c\u5e94\u5f53\u80fd\u63d0\u9ad8\u51fa\u73b0\u8fd9\u79cd\u60c5\u51b5\u7684\u6982\u7387\u3002\uff09", "ExecReScan \u4e0d\u77e5\u9053\u5f53\u524d\u8282\u70b9\u7684\u5b50\u8ba1\u5212\uff0c\u56e0\u6b64\u5fc5\u987b\u81ea\u884c\u901a\u77e5\u5b50\u8ba1\u5212\u54ea\u4e9b\u53c2\u6570\u53d1\u751f\u4e86\u53d8\u5316\u3002"]}, {"code": "case T_BitmapAnd:\n\t\t\tpname = sname = \"BitmapAnd\";\n\t\t\tbreak;", "title": "\u6838\u5fc3\u6e90\u7801\u4e2d\u7684 EXPLAIN \u6807\u8bc6"}], "strategies": [], "description": ["\u5bf9\u5404\u5b50\u8ba1\u5212\u4ea7\u751f\u7684\u4f4d\u56fe\u6c42\u4ea4\u96c6\u3002"], "localization": {"status": "complete", "sources": [], "language": "zh", "original_text": {"/versions/10/description/0": "Intersects bitmaps produced by its child plans.", "/versions/10/facts/0/label": "Core node tag", "/versions/10/facts/1/label": "Structured EXPLAIN Node Type", "/versions/10/facts/2/label": "Inputs", "/versions/10/facts/2/value": "Bitmap-producing child plans", "/versions/10/facts/3/label": "Output", "/versions/10/facts/3/value": "Tuple-location bitmap, not a tuple stream", "/versions/10/facts/4/label": "Executor initializer", "/versions/10/facts/5/label": "Memory mechanism", "/versions/10/tables/0/title": "EXPLAIN labels in this source build", "/versions/10/related/1/label": "Using EXPLAIN", "/versions/10/related/2/label": "Parallel plans", "/versions/10/sections/0/title": "EXPLAIN names and attributes", "/versions/10/sections/1/title": "Memory and temporary storage", "/versions/10/sections/2/title": "Parallel execution and instrumentation", "/versions/10/sections/3/title": "Same-version manual discussion", "/versions/10/sections/4/title": "Examples from this manual build", "/versions/10/sections/5/title": "Executor implementation notes", "/versions/10/sections/6/title": "EXPLAIN identity in core source", "/versions/10/memory/description": "This extraction does not assign a universal memory limit or spill policy to this node. Inspect the same-build implementation and its expressions or provider.", "/versions/10/sections/0/paragraphs/0": "Structured formats use the Node Type above. Text-format spellings can also include operation, strategy, join type, scan direction or aggregation-stage attributes.", "/versions/10/sections/0/paragraphs/1": "Text names recorded by this source: BitmapAnd.", "/versions/10/sections/0/paragraphs/2": "Parallel-aware and parallel-safe are different plan properties. A node running inside a parallel worker is not necessarily a parallel-aware node.", "/versions/10/sections/1/paragraphs/0": "This extraction does not assign a universal memory limit or spill policy to this node. Inspect the same-build implementation and its expressions or provider.", "/versions/10/sections/2/paragraphs/0": "The source callbacks below can coordinate execution or collect worker instrumentation. Their presence is not a blanket claim that this node supports a shared parallel scan or shared state.", "/versions/10/sections/2/paragraphs/1": "Callbacks in this build: none extracted from this node implementation.", "/versions/10/sections/3/paragraphs/0": "BitmapAnd and BitmapOr nodes always report their actual row counts as zero, due to implementation limitations.", "/versions/10/sections/5/paragraphs/0": "NOTES BitmapAnd nodes don't make use of their left and right subtrees, rather they maintain a list of subplans, much like Append nodes. The logic is much simpler than Append, however, since we needn't cope with forward/backward execution.", "/versions/10/sections/5/paragraphs/1": "BitmapAnd plans don't have expression contexts because they never call ExecQual or ExecProject. They don't need any tuple slots either.", "/versions/10/sections/5/paragraphs/2": "call ExecInitNode on each of the plans to be executed and save the results into the array \"bitmapplanstates\".", "/versions/10/sections/5/paragraphs/3": "If at any stage we have a completely empty bitmap, we can fall out without evaluating the remaining subplans, since ANDing them can no longer change the result. (Note: the fact that indxpath.c orders the subplans by selectivity should make this case more likely to occur.)", "/versions/10/sections/5/paragraphs/4": "ExecReScan doesn't know about my subplans, so I have to do changed-parameter signaling myself.", "/versions/10/tables/0/columns/0/label": "Text-format label", "/versions/10/tables/0/columns/1/label": "Structured node identity", "/versions/10/sections/4/blocks/0/paragraphs/0": "Example copied from the PostgreSQL 10.23 manual; it was not executed for this collection.", "/versions/10/sections/4/blocks/0/paragraphs/1": "If there are separate indexes on several of the columns referenced in WHERE , the planner might choose to use an AND or OR combination of the indexes:", "/versions/10/sections/4/blocks/1/paragraphs/0": "Example copied from the PostgreSQL 10.23 manual; it was not executed for this collection.", "/versions/10/sections/4/blocks/1/paragraphs/1": "EXPLAIN has a BUFFERS option that can be used with ANALYZE to get even more run time statistics:"}, "fallback_fields": [], "source_language": "en", "original_snapshot_sha256": "c9cd9742e0123f93ab55b4b735f84eaf9b81a073fa93cb532d9501ec78ebe477"}, "evidence_kind": "source and documentation", "explain_names": ["BitmapAnd"], "partial_modes": [], "comparison_data": {"node_tag": "T_BitmapAnd", "strategies": [], "text_names": ["BitmapAnd"], "initializer": "ExecInitBitmapAnd", "partial_modes": [], "memory_mechanism": "unclassified", "parallel_callbacks": []}, "comparison_hash": "ffac2f4c3c78a9e2f88eb2c2de755f5a69e40f1ac6d7e9bcb4ed08615c9cb803", "explain_prefixes": ["Parallel"], "runtime_verified": false, "source_inventory": {"explain": "src/backend/commands/explain.c", "executor": "src/backend/executor/execProcnode.c", "implementation": "src/backend/executor/nodeBitmapAnd.c"}, "parallel_callbacks": []}, "11": {"facts": [{"label": "\u6838\u5fc3\u8282\u70b9\u6807\u7b7e", "value": "T_BitmapAnd"}, {"label": "\u7ed3\u6784\u5316 EXPLAIN \u8282\u70b9\u7c7b\u578b", "value": "BitmapAnd"}, {"label": "\u8f93\u5165", "value": "\u4ea7\u751f\u4f4d\u56fe\u7684\u5b50\u8ba1\u5212"}, {"label": "\u8f93\u51fa", "value": "\u5143\u7ec4\u4f4d\u7f6e\u4f4d\u56fe\uff0c\u4e0d\u662f\u5143\u7ec4\u6d41"}, {"label": "\u6267\u884c\u5668\u521d\u59cb\u5316\u51fd\u6570", "value": "ExecInitBitmapAnd"}, {"label": "\u5185\u5b58\u673a\u5236", "value": "unclassified"}], "memory": {"evidence": [{"url": "https://ftp.postgresql.org/pub/source/v11.22/postgresql-11.22.tar.bz2", "path": "src/backend/executor/nodeBitmapAnd.c", "label": "src/backend/executor/nodeBitmapAnd.c", "sha256": "e991b34f241eaffa4c664bbd3dd07ec3c418b1003e0a9c071cf008c0510bd038", "archive_sha256": "2cb7c97d7a0d7278851bbc9c61f467b69c094c72b81740b751108e7892ebe1f0"}], "mechanism": "unclassified", "description": "\u672c\u6b21\u62bd\u53d6\u4e0d\u4e3a\u6b64\u8282\u70b9\u8bbe\u5b9a\u7edf\u4e00\u7684\u5185\u5b58\u4e0a\u9650\u6216\u843d\u76d8\u7b56\u7565\u3002\u8bf7\u67e5\u770b\u540c\u4e00\u6784\u5efa\u7684\u5b9e\u73b0\u3001\u76f8\u5173\u8868\u8fbe\u5f0f\u6216\u63d0\u4f9b\u65b9\u3002", "source_notes": []}, "tables": [{"key": "explain-labels", "rows": [{"label": "BitmapAnd", "identity": "BitmapAnd"}], "title": "\u672c\u6784\u5efa\u4e2d\u7684 EXPLAIN \u6807\u7b7e", "columns": [{"key": "label", "label": "\u6587\u672c\u683c\u5f0f\u6807\u7b7e"}, {"key": "identity", "label": "\u7ed3\u6784\u5316\u8282\u70b9\u6807\u8bc6"}]}], "related": [{"url": "/wiki/sql/explain/?v=11", "label": "EXPLAIN"}, {"url": "/docs/11/using-explain.html", "label": "\u4f7f\u7528 EXPLAIN"}, {"url": "/docs/11/parallel-plans.html", "label": "\u5e76\u884c\u8ba1\u5212"}], "release": {"ref": "PostgreSQL 11.22 source archive", "label": "11.22", "major": "11", "channel": "historical", "revision": 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"src/backend/executor/nodeBitmapAnd.c", "label": "src/backend/executor/nodeBitmapAnd.c", "sha256": "e991b34f241eaffa4c664bbd3dd07ec3c418b1003e0a9c071cf008c0510bd038", "archive_sha256": "2cb7c97d7a0d7278851bbc9c61f467b69c094c72b81740b751108e7892ebe1f0"}, {"url": "https://ftp.postgresql.org/pub/source/v11.22/postgresql-11.22.tar.bz2", "path": "src/include/nodes/plannodes.h", "label": "src/include/nodes/plannodes.h", "sha256": "5e0511194183800e8d6eb293fd4b40639c7d3118e2d199c8e7865ba4fa4cf67f", "archive_sha256": "2cb7c97d7a0d7278851bbc9c61f467b69c094c72b81740b751108e7892ebe1f0"}, {"url": "https://pg.center/docs/11/using-explain.html#USING-EXPLAIN-CAVEATS", "path": "using-explain.html", "label": "PostgreSQL 11.22 \u00b7 using-explain", "sha256": "8411bc78085d4737e32d7cca103d859da6c6539e33ec5e2fba46e74c6f199d8a", "language": "en", "original_url": "/docs/11/using-explain.html#USING-EXPLAIN-CAVEATS"}, {"url": "https://pg.center/docs/11/using-explain.html#USING-EXPLAIN-BASICS", "path": "using-explain.html", "label": "PostgreSQL 11.22 \u00b7 using-explain", "sha256": "8411bc78085d4737e32d7cca103d859da6c6539e33ec5e2fba46e74c6f199d8a", "language": "en", "original_url": "/docs/11/using-explain.html#USING-EXPLAIN-BASICS"}, {"url": "https://pg.center/docs/11/using-explain.html#USING-EXPLAIN-ANALYZE", "path": "using-explain.html", "label": "PostgreSQL 11.22 \u00b7 using-explain", "sha256": "8411bc78085d4737e32d7cca103d859da6c6539e33ec5e2fba46e74c6f199d8a", "language": "en", "original_url": "/docs/11/using-explain.html#USING-EXPLAIN-ANALYZE"}], "node_tag": "T_BitmapAnd", "sections": [{"title": "EXPLAIN \u540d\u79f0\u4e0e\u5c5e\u6027", "paragraphs": ["\u7ed3\u6784\u5316\u683c\u5f0f\u4f7f\u7528\u4e0a\u8ff0 Node Type\u3002\u6587\u672c\u683c\u5f0f\u540d\u79f0\u8fd8\u53ef\u80fd\u5305\u542b\u64cd\u4f5c\u3001\u7b56\u7565\u3001\u8fde\u63a5\u7c7b\u578b\u3001\u626b\u63cf\u65b9\u5411\u6216\u805a\u5408\u9636\u6bb5\u5c5e\u6027\u3002", "\u6b64\u6e90\u7801\u8bb0\u5f55\u7684\u6587\u672c\u540d\u79f0\uff1aBitmapAnd.", "\u5e76\u884c\u611f\u77e5\u4e0e\u5e76\u884c\u5b89\u5168\u662f\u4e0d\u540c\u7684\u8ba1\u5212\u5c5e\u6027\u3002\u5728\u5e76\u884c\u5de5\u4f5c\u8fdb\u7a0b\u5185\u8fd0\u884c\u7684\u8282\u70b9\u4e0d\u4e00\u5b9a\u662f\u5e76\u884c\u611f\u77e5\u8282\u70b9\u3002"]}, {"title": "\u5185\u5b58\u4e0e\u4e34\u65f6\u5b58\u50a8", "paragraphs": ["\u672c\u6b21\u62bd\u53d6\u4e0d\u4e3a\u6b64\u8282\u70b9\u8bbe\u5b9a\u7edf\u4e00\u7684\u5185\u5b58\u4e0a\u9650\u6216\u843d\u76d8\u7b56\u7565\u3002\u8bf7\u67e5\u770b\u540c\u4e00\u6784\u5efa\u7684\u5b9e\u73b0\u3001\u76f8\u5173\u8868\u8fbe\u5f0f\u6216\u63d0\u4f9b\u65b9\u3002"]}, {"title": "\u5e76\u884c\u6267\u884c\u4e0e\u8fd0\u884c\u4fe1\u606f\u91c7\u96c6", "paragraphs": ["\u4ee5\u4e0b\u6e90\u7801\u56de\u8c03\u53ef\u4ee5\u534f\u8c03\u6267\u884c\u6216\u6536\u96c6\u5de5\u4f5c\u8fdb\u7a0b\u7684\u6d4b\u91cf\u6570\u636e\u3002\u56de\u8c03\u5b58\u5728\u4e0d\u4ee3\u8868\u8be5\u8282\u70b9\u666e\u904d\u652f\u6301\u5171\u4eab\u5e76\u884c\u626b\u63cf\u6216\u5171\u4eab\u72b6\u6001\u3002", "\u6b64\u6784\u5efa\u7684\u56de\u8c03\uff1anone extracted from this node implementation."]}, {"title": "\u540c\u7248\u672c\u624b\u518c\u8bf4\u660e", "paragraphs": ["\u7531\u4e8e\u5b9e\u73b0\u4e0a\u7684\u9650\u5236\uff0cBitmapAnd \u548c BitmapOr \u8282\u70b9\u62a5\u544a\u7684\u5b9e\u9645\u884c\u6570\u59cb\u7ec8\u4e3a\u96f6\u3002"]}, {"title": "\u672c\u7248\u624b\u518c\u4e2d\u7684\u793a\u4f8b", "blocks": [{"code": "EXPLAIN SELECT * FROM tenk1 WHERE unique1 < 100 AND unique2 > 9000;\n\n QUERY PLAN\n-------------------------------------------------------------------------------------\n Bitmap Heap Scan on tenk1 (cost=25.08..60.21 rows=10 width=244)\n Recheck Cond: ((unique1 < 100) AND (unique2 > 9000))\n -> BitmapAnd (cost=25.08..25.08 rows=10 width=0)\n -> Bitmap Index Scan on tenk1_unique1 (cost=0.00..5.04 rows=101 width=0)\n Index Cond: (unique1 < 100)\n -> Bitmap Index Scan on tenk1_unique2 (cost=0.00..19.78 rows=999 width=0)\n Index Cond: (unique2 > 9000)", "source": {"url": "/docs/11/using-explain.html#USING-EXPLAIN-BASICS", "path": "using-explain.html", "label": "PostgreSQL 11.22 \u00b7 using-explain", "sha256": "8411bc78085d4737e32d7cca103d859da6c6539e33ec5e2fba46e74c6f199d8a"}, "paragraphs": ["\u793a\u4f8b\u6458\u81ea PostgreSQL 11.22 \u624b\u518c\uff1b\u672c\u767e\u79d1\u672a\u5b9e\u9645\u6267\u884c\u6b64\u793a\u4f8b\u3002", "\u5982\u679c WHERE \u5f15\u7528\u7684\u591a\u4e2a\u5217\u4e0a\u5206\u522b\u5efa\u6709\u7d22\u5f15\uff0c\u89c4\u5212\u5668\u53ef\u80fd\u9009\u62e9\u7528 AND \u6216 OR \u7ec4\u5408\u8fd9\u4e9b\u7d22\u5f15\uff1a"]}, {"code": "EXPLAIN (ANALYZE, BUFFERS) SELECT * FROM tenk1 WHERE unique1 < 100 AND unique2 > 9000;\n\n QUERY PLAN\n---------------------------------------------------------------------------------------------------------------------------------\n Bitmap Heap Scan on tenk1 (cost=25.08..60.21 rows=10 width=244) (actual time=0.323..0.342 rows=10 loops=1)\n Recheck Cond: ((unique1 < 100) AND (unique2 > 9000))\n Buffers: shared hit=15\n -> BitmapAnd (cost=25.08..25.08 rows=10 width=0) (actual time=0.309..0.309 rows=0 loops=1)\n Buffers: shared hit=7\n -> Bitmap Index Scan on tenk1_unique1 (cost=0.00..5.04 rows=101 width=0) (actual time=0.043..0.043 rows=100 loops=1)\n Index Cond: (unique1 < 100)\n Buffers: shared hit=2\n -> Bitmap Index Scan on tenk1_unique2 (cost=0.00..19.78 rows=999 width=0) (actual time=0.227..0.227 rows=999 loops=1)\n Index Cond: (unique2 > 9000)\n Buffers: shared hit=5\n Planning time: 0.088 ms\n Execution time: 0.423 ms", "source": {"url": "/docs/11/using-explain.html#USING-EXPLAIN-ANALYZE", "path": "using-explain.html", "label": "PostgreSQL 11.22 \u00b7 using-explain", "sha256": "8411bc78085d4737e32d7cca103d859da6c6539e33ec5e2fba46e74c6f199d8a"}, "paragraphs": ["\u793a\u4f8b\u6458\u81ea PostgreSQL 11.22 \u624b\u518c\uff1b\u672c\u767e\u79d1\u672a\u5b9e\u9645\u6267\u884c\u6b64\u793a\u4f8b\u3002", "EXPLAIN \u7684 BUFFERS \u9009\u9879\u53ef\u4e0e ANALYZE \u914d\u5408\u4f7f\u7528\uff0c\u4ee5\u83b7\u53d6\u66f4\u591a\u8fd0\u884c\u65f6\u7edf\u8ba1\u4fe1\u606f\uff1a"]}]}, {"title": "\u6267\u884c\u5668\u5b9e\u73b0\u8bf4\u660e", "paragraphs": ["\u8bf4\u660e\uff1aBitmapAnd \u4e0d\u4f7f\u7528\u5de6\u53f3\u5b50\u6811\uff0c\u800c\u50cf Append \u4e00\u6837\u7ef4\u62a4\u5b50\u8ba1\u5212\u5217\u8868\u3002\u4e0d\u8fc7\u5176\u903b\u8f91\u6bd4 Append \u7b80\u5355\u5f97\u591a\uff0c\u56e0\u4e3a\u65e0\u9700\u5904\u7406\u6b63\u5411\u6216\u53cd\u5411\u6267\u884c\u3002", "\u5bf9\u6bcf\u4e2a\u5f85\u6267\u884c\u8ba1\u5212\u8c03\u7528 ExecInitNode\uff0c\u5e76\u5c06\u7ed3\u679c\u4fdd\u5b58\u5230 bitmapplanstates \u6570\u7ec4\u3002", "BitmapAnd \u8ba1\u5212\u6ca1\u6709\u8868\u8fbe\u5f0f\u4e0a\u4e0b\u6587\uff0c\u56e0\u4e3a\u5b83\u4eec\u4ece\u4e0d\u8c03\u7528 ExecQual \u6216 ExecProject\uff0c\u4e5f\u4e0d\u9700\u8981\u5143\u7ec4\u69fd\u3002", "\u5982\u679c\u5728\u4efb\u4f55\u9636\u6bb5\u5f97\u5230\u5b8c\u5168\u4e3a\u7a7a\u7684\u4f4d\u56fe\uff0c\u5c31\u53ef\u4ee5\u76f4\u63a5\u9000\u51fa\uff0c\u65e0\u9700\u6267\u884c\u5269\u4f59\u5b50\u8ba1\u5212\uff0c\u56e0\u4e3a\u518d\u8fdb\u884c AND \u8fd0\u7b97\u4e5f\u4e0d\u4f1a\u6539\u53d8\u7ed3\u679c\u3002\uff08\u6ce8\u610f\uff1aindxpath.c \u6309\u9009\u62e9\u7387\u5bf9\u5b50\u8ba1\u5212\u6392\u5e8f\uff0c\u5e94\u5f53\u80fd\u63d0\u9ad8\u51fa\u73b0\u8fd9\u79cd\u60c5\u51b5\u7684\u6982\u7387\u3002\uff09", "ExecReScan \u4e0d\u77e5\u9053\u5f53\u524d\u8282\u70b9\u7684\u5b50\u8ba1\u5212\uff0c\u56e0\u6b64\u5fc5\u987b\u81ea\u884c\u901a\u77e5\u5b50\u8ba1\u5212\u54ea\u4e9b\u53c2\u6570\u53d1\u751f\u4e86\u53d8\u5316\u3002"]}, {"code": "case T_BitmapAnd:\n\t\t\tpname = sname = \"BitmapAnd\";\n\t\t\tbreak;", "title": "\u6838\u5fc3\u6e90\u7801\u4e2d\u7684 EXPLAIN \u6807\u8bc6"}], "strategies": [], "description": ["\u5bf9\u5404\u5b50\u8ba1\u5212\u4ea7\u751f\u7684\u4f4d\u56fe\u6c42\u4ea4\u96c6\u3002"], "localization": {"status": "complete", "sources": [], "language": "zh", "original_text": {"/versions/11/description/0": "Intersects bitmaps produced by its child plans.", "/versions/11/facts/0/label": "Core node tag", "/versions/11/facts/1/label": "Structured EXPLAIN Node Type", "/versions/11/facts/2/label": "Inputs", "/versions/11/facts/2/value": "Bitmap-producing child plans", "/versions/11/facts/3/label": "Output", "/versions/11/facts/3/value": "Tuple-location bitmap, not a tuple stream", "/versions/11/facts/4/label": "Executor initializer", "/versions/11/facts/5/label": "Memory mechanism", "/versions/11/tables/0/title": "EXPLAIN labels in this source build", "/versions/11/related/1/label": "Using EXPLAIN", "/versions/11/related/2/label": "Parallel plans", "/versions/11/sections/0/title": "EXPLAIN names and attributes", "/versions/11/sections/1/title": "Memory and temporary storage", "/versions/11/sections/2/title": "Parallel execution and instrumentation", "/versions/11/sections/3/title": "Same-version manual discussion", "/versions/11/sections/4/title": "Examples from this manual build", "/versions/11/sections/5/title": "Executor implementation notes", "/versions/11/sections/6/title": "EXPLAIN identity in core source", "/versions/11/memory/description": "This extraction does not assign a universal memory limit or spill policy to this node. Inspect the same-build implementation and its expressions or provider.", "/versions/11/sections/0/paragraphs/0": "Structured formats use the Node Type above. Text-format spellings can also include operation, strategy, join type, scan direction or aggregation-stage attributes.", "/versions/11/sections/0/paragraphs/1": "Text names recorded by this source: BitmapAnd.", "/versions/11/sections/0/paragraphs/2": "Parallel-aware and parallel-safe are different plan properties. A node running inside a parallel worker is not necessarily a parallel-aware node.", "/versions/11/sections/1/paragraphs/0": "This extraction does not assign a universal memory limit or spill policy to this node. Inspect the same-build implementation and its expressions or provider.", "/versions/11/sections/2/paragraphs/0": "The source callbacks below can coordinate execution or collect worker instrumentation. Their presence is not a blanket claim that this node supports a shared parallel scan or shared state.", "/versions/11/sections/2/paragraphs/1": "Callbacks in this build: none extracted from this node implementation.", "/versions/11/sections/3/paragraphs/0": "BitmapAnd and BitmapOr nodes always report their actual row counts as zero, due to implementation limitations.", "/versions/11/sections/5/paragraphs/0": "NOTES BitmapAnd nodes don't make use of their left and right subtrees, rather they maintain a list of subplans, much like Append nodes. The logic is much simpler than Append, however, since we needn't cope with forward/backward execution.", "/versions/11/sections/5/paragraphs/1": "call ExecInitNode on each of the plans to be executed and save the results into the array \"bitmapplanstates\".", "/versions/11/sections/5/paragraphs/2": "BitmapAnd plans don't have expression contexts because they never call ExecQual or ExecProject. They don't need any tuple slots either.", "/versions/11/sections/5/paragraphs/3": "If at any stage we have a completely empty bitmap, we can fall out without evaluating the remaining subplans, since ANDing them can no longer change the result. (Note: the fact that indxpath.c orders the subplans by selectivity should make this case more likely to occur.)", "/versions/11/sections/5/paragraphs/4": "ExecReScan doesn't know about my subplans, so I have to do changed-parameter signaling myself.", "/versions/11/tables/0/columns/0/label": "Text-format label", "/versions/11/tables/0/columns/1/label": "Structured node identity", "/versions/11/sections/4/blocks/0/paragraphs/0": "Example copied from the PostgreSQL 11.22 manual; it was not executed for this collection.", "/versions/11/sections/4/blocks/0/paragraphs/1": "If there are separate indexes on several of the columns referenced in WHERE , the planner might choose to use an AND or OR combination of the indexes:", "/versions/11/sections/4/blocks/1/paragraphs/0": "Example copied from the PostgreSQL 11.22 manual; it was not executed for this collection.", "/versions/11/sections/4/blocks/1/paragraphs/1": "EXPLAIN has a BUFFERS option that can be used with ANALYZE to get even more run time statistics:"}, "fallback_fields": [], "source_language": "en", "original_snapshot_sha256": "dcef7ba2ff4c459ce84d5d7a2482a19bd1bb826be441d86ea9c060e7bfac479a"}, "evidence_kind": "source and documentation", "explain_names": ["BitmapAnd"], "partial_modes": [], "comparison_data": {"node_tag": "T_BitmapAnd", "strategies": [], "text_names": ["BitmapAnd"], "initializer": "ExecInitBitmapAnd", "partial_modes": [], "memory_mechanism": "unclassified", "parallel_callbacks": []}, "comparison_hash": "ffac2f4c3c78a9e2f88eb2c2de755f5a69e40f1ac6d7e9bcb4ed08615c9cb803", "explain_prefixes": ["Parallel"], "runtime_verified": false, "source_inventory": {"explain": "src/backend/commands/explain.c", "executor": "src/backend/executor/execProcnode.c", "implementation": "src/backend/executor/nodeBitmapAnd.c"}, "parallel_callbacks": []}, "12": {"facts": [{"label": "\u6838\u5fc3\u8282\u70b9\u6807\u7b7e", "value": "T_BitmapAnd"}, {"label": "\u7ed3\u6784\u5316 EXPLAIN \u8282\u70b9\u7c7b\u578b", "value": "BitmapAnd"}, {"label": "\u8f93\u5165", "value": "\u4ea7\u751f\u4f4d\u56fe\u7684\u5b50\u8ba1\u5212"}, {"label": "\u8f93\u51fa", "value": "\u5143\u7ec4\u4f4d\u7f6e\u4f4d\u56fe\uff0c\u4e0d\u662f\u5143\u7ec4\u6d41"}, {"label": "\u6267\u884c\u5668\u521d\u59cb\u5316\u51fd\u6570", "value": "ExecInitBitmapAnd"}, {"label": "\u5185\u5b58\u673a\u5236", "value": "unclassified"}], "memory": {"evidence": [{"url": "https://ftp.postgresql.org/pub/source/v12.22/postgresql-12.22.tar.bz2", "path": "src/backend/executor/nodeBitmapAnd.c", "label": "src/backend/executor/nodeBitmapAnd.c", "sha256": "56b28d4a22ee8f6234f26789dcd26140de350d94c41b91e955c061ff530cba2f", "archive_sha256": "8df3c0474782589d3c6f374b5133b1bd14d168086edbc13c6e72e67dd4527a3b"}], "mechanism": "unclassified", "description": 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"src/backend/executor/nodeBitmapAnd.c", "label": "src/backend/executor/nodeBitmapAnd.c", "sha256": "56b28d4a22ee8f6234f26789dcd26140de350d94c41b91e955c061ff530cba2f", "archive_sha256": "8df3c0474782589d3c6f374b5133b1bd14d168086edbc13c6e72e67dd4527a3b"}, {"url": "https://ftp.postgresql.org/pub/source/v12.22/postgresql-12.22.tar.bz2", "path": "src/include/nodes/plannodes.h", "label": "src/include/nodes/plannodes.h", "sha256": "b0c4a0aeb48660ce06e5e700d5529ca9066fd16682bd15783d6e71b5420b07b0", "archive_sha256": "8df3c0474782589d3c6f374b5133b1bd14d168086edbc13c6e72e67dd4527a3b"}, {"url": "https://pg.center/docs/12/using-explain.html#USING-EXPLAIN-CAVEATS", "path": "using-explain.html", "label": "PostgreSQL 12.22 \u00b7 using-explain", "sha256": "06297525f2180b07e752837a3351be9c871b56559f535bcd0a67dec9baac10c0", "language": "en", "original_url": "/docs/12/using-explain.html#USING-EXPLAIN-CAVEATS"}, {"url": "https://pg.center/docs/12/using-explain.html#USING-EXPLAIN-BASICS", "path": "using-explain.html", "label": "PostgreSQL 12.22 \u00b7 using-explain", "sha256": "06297525f2180b07e752837a3351be9c871b56559f535bcd0a67dec9baac10c0", "language": "en", "original_url": "/docs/12/using-explain.html#USING-EXPLAIN-BASICS"}, {"url": "https://pg.center/docs/12/using-explain.html#USING-EXPLAIN-ANALYZE", "path": "using-explain.html", "label": "PostgreSQL 12.22 \u00b7 using-explain", "sha256": "06297525f2180b07e752837a3351be9c871b56559f535bcd0a67dec9baac10c0", "language": "en", "original_url": "/docs/12/using-explain.html#USING-EXPLAIN-ANALYZE"}], "node_tag": "T_BitmapAnd", "sections": [{"title": "EXPLAIN \u540d\u79f0\u4e0e\u5c5e\u6027", "paragraphs": ["\u7ed3\u6784\u5316\u683c\u5f0f\u4f7f\u7528\u4e0a\u8ff0 Node Type\u3002\u6587\u672c\u683c\u5f0f\u540d\u79f0\u8fd8\u53ef\u80fd\u5305\u542b\u64cd\u4f5c\u3001\u7b56\u7565\u3001\u8fde\u63a5\u7c7b\u578b\u3001\u626b\u63cf\u65b9\u5411\u6216\u805a\u5408\u9636\u6bb5\u5c5e\u6027\u3002", "\u6b64\u6e90\u7801\u8bb0\u5f55\u7684\u6587\u672c\u540d\u79f0\uff1aBitmapAnd.", "\u5e76\u884c\u611f\u77e5\u4e0e\u5e76\u884c\u5b89\u5168\u662f\u4e0d\u540c\u7684\u8ba1\u5212\u5c5e\u6027\u3002\u5728\u5e76\u884c\u5de5\u4f5c\u8fdb\u7a0b\u5185\u8fd0\u884c\u7684\u8282\u70b9\u4e0d\u4e00\u5b9a\u662f\u5e76\u884c\u611f\u77e5\u8282\u70b9\u3002"]}, {"title": "\u5185\u5b58\u4e0e\u4e34\u65f6\u5b58\u50a8", "paragraphs": ["\u672c\u6b21\u62bd\u53d6\u4e0d\u4e3a\u6b64\u8282\u70b9\u8bbe\u5b9a\u7edf\u4e00\u7684\u5185\u5b58\u4e0a\u9650\u6216\u843d\u76d8\u7b56\u7565\u3002\u8bf7\u67e5\u770b\u540c\u4e00\u6784\u5efa\u7684\u5b9e\u73b0\u3001\u76f8\u5173\u8868\u8fbe\u5f0f\u6216\u63d0\u4f9b\u65b9\u3002"]}, {"title": "\u5e76\u884c\u6267\u884c\u4e0e\u8fd0\u884c\u4fe1\u606f\u91c7\u96c6", "paragraphs": ["\u4ee5\u4e0b\u6e90\u7801\u56de\u8c03\u53ef\u4ee5\u534f\u8c03\u6267\u884c\u6216\u6536\u96c6\u5de5\u4f5c\u8fdb\u7a0b\u7684\u6d4b\u91cf\u6570\u636e\u3002\u56de\u8c03\u5b58\u5728\u4e0d\u4ee3\u8868\u8be5\u8282\u70b9\u666e\u904d\u652f\u6301\u5171\u4eab\u5e76\u884c\u626b\u63cf\u6216\u5171\u4eab\u72b6\u6001\u3002", "\u6b64\u6784\u5efa\u7684\u56de\u8c03\uff1anone extracted from this node implementation."]}, {"title": "\u540c\u7248\u672c\u624b\u518c\u8bf4\u660e", "paragraphs": ["\u7531\u4e8e\u5b9e\u73b0\u4e0a\u7684\u9650\u5236\uff0cBitmapAnd \u548c BitmapOr \u8282\u70b9\u62a5\u544a\u7684\u5b9e\u9645\u884c\u6570\u59cb\u7ec8\u4e3a\u96f6\u3002"]}, {"title": "\u672c\u7248\u624b\u518c\u4e2d\u7684\u793a\u4f8b", "blocks": [{"code": "EXPLAIN SELECT * FROM tenk1 WHERE unique1 < 100 AND unique2 > 9000;\n\n QUERY PLAN\n-------------------------------------------------------------------------------------\n Bitmap Heap Scan on tenk1 (cost=25.08..60.21 rows=10 width=244)\n Recheck Cond: ((unique1 < 100) AND (unique2 > 9000))\n -> BitmapAnd (cost=25.08..25.08 rows=10 width=0)\n -> Bitmap Index Scan on tenk1_unique1 (cost=0.00..5.04 rows=101 width=0)\n Index Cond: (unique1 < 100)\n -> Bitmap Index Scan on tenk1_unique2 (cost=0.00..19.78 rows=999 width=0)\n Index Cond: (unique2 > 9000)", "source": {"url": "/docs/12/using-explain.html#USING-EXPLAIN-BASICS", "path": "using-explain.html", "label": "PostgreSQL 12.22 \u00b7 using-explain", "sha256": "06297525f2180b07e752837a3351be9c871b56559f535bcd0a67dec9baac10c0"}, "paragraphs": ["\u793a\u4f8b\u6458\u81ea PostgreSQL 12.22 \u624b\u518c\uff1b\u672c\u767e\u79d1\u672a\u5b9e\u9645\u6267\u884c\u6b64\u793a\u4f8b\u3002", "\u5982\u679c WHERE \u5f15\u7528\u7684\u591a\u4e2a\u5217\u4e0a\u5206\u522b\u5efa\u6709\u7d22\u5f15\uff0c\u89c4\u5212\u5668\u53ef\u80fd\u9009\u62e9\u7528 AND \u6216 OR \u7ec4\u5408\u8fd9\u4e9b\u7d22\u5f15\uff1a"]}, {"code": "EXPLAIN (ANALYZE, BUFFERS) SELECT * FROM tenk1 WHERE unique1 < 100 AND unique2 > 9000;\n\n QUERY PLAN\n---------------------------------------------------------------------------------------------------------------------------------\n Bitmap Heap Scan on tenk1 (cost=25.08..60.21 rows=10 width=244) (actual time=0.323..0.342 rows=10 loops=1)\n Recheck Cond: ((unique1 < 100) AND (unique2 > 9000))\n Buffers: shared hit=15\n -> BitmapAnd (cost=25.08..25.08 rows=10 width=0) (actual time=0.309..0.309 rows=0 loops=1)\n Buffers: shared hit=7\n -> Bitmap Index Scan on tenk1_unique1 (cost=0.00..5.04 rows=101 width=0) (actual time=0.043..0.043 rows=100 loops=1)\n Index Cond: (unique1 < 100)\n Buffers: shared hit=2\n -> Bitmap Index Scan on tenk1_unique2 (cost=0.00..19.78 rows=999 width=0) (actual time=0.227..0.227 rows=999 loops=1)\n Index Cond: (unique2 > 9000)\n Buffers: shared hit=5\n Planning time: 0.088 ms\n Execution time: 0.423 ms", "source": {"url": "/docs/12/using-explain.html#USING-EXPLAIN-ANALYZE", "path": "using-explain.html", "label": "PostgreSQL 12.22 \u00b7 using-explain", "sha256": "06297525f2180b07e752837a3351be9c871b56559f535bcd0a67dec9baac10c0"}, "paragraphs": ["\u793a\u4f8b\u6458\u81ea PostgreSQL 12.22 \u624b\u518c\uff1b\u672c\u767e\u79d1\u672a\u5b9e\u9645\u6267\u884c\u6b64\u793a\u4f8b\u3002", "EXPLAIN \u7684 BUFFERS \u9009\u9879\u53ef\u4e0e ANALYZE \u914d\u5408\u4f7f\u7528\uff0c\u4ee5\u83b7\u53d6\u66f4\u591a\u8fd0\u884c\u65f6\u7edf\u8ba1\u4fe1\u606f\uff1a"]}]}, {"title": "\u6267\u884c\u5668\u5b9e\u73b0\u8bf4\u660e", "paragraphs": ["\u8bf4\u660e\uff1aBitmapAnd \u4e0d\u4f7f\u7528\u5de6\u53f3\u5b50\u6811\uff0c\u800c\u50cf Append \u4e00\u6837\u7ef4\u62a4\u5b50\u8ba1\u5212\u5217\u8868\u3002\u4e0d\u8fc7\u5176\u903b\u8f91\u6bd4 Append \u7b80\u5355\u5f97\u591a\uff0c\u56e0\u4e3a\u65e0\u9700\u5904\u7406\u6b63\u5411\u6216\u53cd\u5411\u6267\u884c\u3002", "\u5bf9\u6bcf\u4e2a\u5f85\u6267\u884c\u8ba1\u5212\u8c03\u7528 ExecInitNode\uff0c\u5e76\u5c06\u7ed3\u679c\u4fdd\u5b58\u5230 bitmapplanstates \u6570\u7ec4\u3002", "BitmapAnd \u8ba1\u5212\u6ca1\u6709\u8868\u8fbe\u5f0f\u4e0a\u4e0b\u6587\uff0c\u56e0\u4e3a\u5b83\u4eec\u4ece\u4e0d\u8c03\u7528 ExecQual \u6216 ExecProject\uff0c\u4e5f\u4e0d\u9700\u8981\u5143\u7ec4\u69fd\u3002", "\u5982\u679c\u5728\u4efb\u4f55\u9636\u6bb5\u5f97\u5230\u5b8c\u5168\u4e3a\u7a7a\u7684\u4f4d\u56fe\uff0c\u5c31\u53ef\u4ee5\u76f4\u63a5\u9000\u51fa\uff0c\u65e0\u9700\u6267\u884c\u5269\u4f59\u5b50\u8ba1\u5212\uff0c\u56e0\u4e3a\u518d\u8fdb\u884c AND \u8fd0\u7b97\u4e5f\u4e0d\u4f1a\u6539\u53d8\u7ed3\u679c\u3002\uff08\u6ce8\u610f\uff1aindxpath.c \u6309\u9009\u62e9\u7387\u5bf9\u5b50\u8ba1\u5212\u6392\u5e8f\uff0c\u5e94\u5f53\u80fd\u63d0\u9ad8\u51fa\u73b0\u8fd9\u79cd\u60c5\u51b5\u7684\u6982\u7387\u3002\uff09", "ExecReScan \u4e0d\u77e5\u9053\u5f53\u524d\u8282\u70b9\u7684\u5b50\u8ba1\u5212\uff0c\u56e0\u6b64\u5fc5\u987b\u81ea\u884c\u901a\u77e5\u5b50\u8ba1\u5212\u54ea\u4e9b\u53c2\u6570\u53d1\u751f\u4e86\u53d8\u5316\u3002"]}, {"code": "case T_BitmapAnd:\n\t\t\tpname = sname = \"BitmapAnd\";\n\t\t\tbreak;", "title": "\u6838\u5fc3\u6e90\u7801\u4e2d\u7684 EXPLAIN \u6807\u8bc6"}], "strategies": [], "description": ["\u5bf9\u5404\u5b50\u8ba1\u5212\u4ea7\u751f\u7684\u4f4d\u56fe\u6c42\u4ea4\u96c6\u3002"], "localization": {"status": "complete", "sources": [], "language": "zh", "original_text": {"/versions/12/description/0": "Intersects bitmaps produced by its child plans.", "/versions/12/facts/0/label": "Core node tag", "/versions/12/facts/1/label": "Structured EXPLAIN Node Type", "/versions/12/facts/2/label": "Inputs", "/versions/12/facts/2/value": "Bitmap-producing child plans", "/versions/12/facts/3/label": "Output", "/versions/12/facts/3/value": "Tuple-location bitmap, not a tuple stream", "/versions/12/facts/4/label": "Executor initializer", "/versions/12/facts/5/label": "Memory mechanism", "/versions/12/tables/0/title": "EXPLAIN labels in this source build", "/versions/12/related/1/label": "Using EXPLAIN", "/versions/12/related/2/label": "Parallel plans", "/versions/12/sections/0/title": "EXPLAIN names and attributes", "/versions/12/sections/1/title": "Memory and temporary storage", "/versions/12/sections/2/title": "Parallel execution and instrumentation", "/versions/12/sections/3/title": "Same-version manual discussion", "/versions/12/sections/4/title": "Examples from this manual build", "/versions/12/sections/5/title": "Executor implementation notes", "/versions/12/sections/6/title": "EXPLAIN identity in core source", "/versions/12/memory/description": "This extraction does not assign a universal memory limit or spill policy to this node. Inspect the same-build implementation and its expressions or provider.", "/versions/12/sections/0/paragraphs/0": "Structured formats use the Node Type above. Text-format spellings can also include operation, strategy, join type, scan direction or aggregation-stage attributes.", "/versions/12/sections/0/paragraphs/1": "Text names recorded by this source: BitmapAnd.", "/versions/12/sections/0/paragraphs/2": "Parallel-aware and parallel-safe are different plan properties. A node running inside a parallel worker is not necessarily a parallel-aware node.", "/versions/12/sections/1/paragraphs/0": "This extraction does not assign a universal memory limit or spill policy to this node. Inspect the same-build implementation and its expressions or provider.", "/versions/12/sections/2/paragraphs/0": "The source callbacks below can coordinate execution or collect worker instrumentation. Their presence is not a blanket claim that this node supports a shared parallel scan or shared state.", "/versions/12/sections/2/paragraphs/1": "Callbacks in this build: none extracted from this node implementation.", "/versions/12/sections/3/paragraphs/0": "BitmapAnd and BitmapOr nodes always report their actual row counts as zero, due to implementation limitations.", "/versions/12/sections/5/paragraphs/0": "NOTES BitmapAnd nodes don't make use of their left and right subtrees, rather they maintain a list of subplans, much like Append nodes. The logic is much simpler than Append, however, since we needn't cope with forward/backward execution.", "/versions/12/sections/5/paragraphs/1": "call ExecInitNode on each of the plans to be executed and save the results into the array \"bitmapplanstates\".", "/versions/12/sections/5/paragraphs/2": "BitmapAnd plans don't have expression contexts because they never call ExecQual or ExecProject. They don't need any tuple slots either.", "/versions/12/sections/5/paragraphs/3": "If at any stage we have a completely empty bitmap, we can fall out without evaluating the remaining subplans, since ANDing them can no longer change the result. (Note: the fact that indxpath.c orders the subplans by selectivity should make this case more likely to occur.)", "/versions/12/sections/5/paragraphs/4": "ExecReScan doesn't know about my subplans, so I have to do changed-parameter signaling myself.", "/versions/12/tables/0/columns/0/label": "Text-format label", "/versions/12/tables/0/columns/1/label": "Structured node identity", "/versions/12/sections/4/blocks/0/paragraphs/0": "Example copied from the PostgreSQL 12.22 manual; it was not executed for this collection.", "/versions/12/sections/4/blocks/0/paragraphs/1": "If there are separate indexes on several of the columns referenced in WHERE , the planner might choose to use an AND or OR combination of the indexes:", "/versions/12/sections/4/blocks/1/paragraphs/0": "Example copied from the PostgreSQL 12.22 manual; it was not executed for this collection.", "/versions/12/sections/4/blocks/1/paragraphs/1": "EXPLAIN has a BUFFERS option that can be used with ANALYZE to get even more run time statistics:"}, "fallback_fields": [], "source_language": "en", "original_snapshot_sha256": "05fc7d30e88e504bc87e7da5a3827c3144641ac50102cb15ca2552605cad7706"}, "evidence_kind": "source and documentation", "explain_names": ["BitmapAnd"], "partial_modes": [], "comparison_data": {"node_tag": "T_BitmapAnd", "strategies": [], "text_names": ["BitmapAnd"], "initializer": "ExecInitBitmapAnd", "partial_modes": [], "memory_mechanism": "unclassified", "parallel_callbacks": []}, "comparison_hash": "ffac2f4c3c78a9e2f88eb2c2de755f5a69e40f1ac6d7e9bcb4ed08615c9cb803", "explain_prefixes": ["Parallel"], "runtime_verified": false, "source_inventory": {"explain": "src/backend/commands/explain.c", "executor": "src/backend/executor/execProcnode.c", "implementation": "src/backend/executor/nodeBitmapAnd.c"}, "parallel_callbacks": []}, "13": {"facts": [{"label": "\u6838\u5fc3\u8282\u70b9\u6807\u7b7e", "value": "T_BitmapAnd"}, {"label": "\u7ed3\u6784\u5316 EXPLAIN \u8282\u70b9\u7c7b\u578b", "value": "BitmapAnd"}, {"label": "\u8f93\u5165", "value": "\u4ea7\u751f\u4f4d\u56fe\u7684\u5b50\u8ba1\u5212"}, {"label": "\u8f93\u51fa", "value": "\u5143\u7ec4\u4f4d\u7f6e\u4f4d\u56fe\uff0c\u4e0d\u662f\u5143\u7ec4\u6d41"}, {"label": "\u6267\u884c\u5668\u521d\u59cb\u5316\u51fd\u6570", "value": "ExecInitBitmapAnd"}, {"label": "\u5185\u5b58\u673a\u5236", "value": "unclassified"}], "memory": {"evidence": [{"url": "https://ftp.postgresql.org/pub/source/v13.23/postgresql-13.23.tar.bz2", "path": "src/backend/executor/nodeBitmapAnd.c", "label": "src/backend/executor/nodeBitmapAnd.c", "sha256": "189bd085e01ce8519420b49d790ca2065613c64c7022641bfcb81072f3efcb2e", "archive_sha256": "6ec3c82726af92b7dec873fa1cdf881eca92a4219787dfad05acb6b10e041fd6"}], "mechanism": "unclassified", "description": 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"src/backend/executor/nodeBitmapAnd.c", "label": "src/backend/executor/nodeBitmapAnd.c", "sha256": "189bd085e01ce8519420b49d790ca2065613c64c7022641bfcb81072f3efcb2e", "archive_sha256": "6ec3c82726af92b7dec873fa1cdf881eca92a4219787dfad05acb6b10e041fd6"}, {"url": "https://ftp.postgresql.org/pub/source/v13.23/postgresql-13.23.tar.bz2", "path": "src/include/nodes/plannodes.h", "label": "src/include/nodes/plannodes.h", "sha256": "dcb296833777b02008c4b6bae8e8f7c6423b7ffba21f36702597c9d596d039ab", "archive_sha256": "6ec3c82726af92b7dec873fa1cdf881eca92a4219787dfad05acb6b10e041fd6"}, {"url": "https://pg.center/docs/13/using-explain.html#USING-EXPLAIN-CAVEATS", "path": "using-explain.html", "label": "PostgreSQL 13.23 \u00b7 using-explain", "sha256": "650fd8629382d5dc8f9f8412c50ec5f32442a9ad2f98ca88e5348a7c2bd0ac7a", "language": "en", "original_url": "/docs/13/using-explain.html#USING-EXPLAIN-CAVEATS"}, {"url": "https://pg.center/docs/13/using-explain.html#USING-EXPLAIN-BASICS", "path": "using-explain.html", "label": "PostgreSQL 13.23 \u00b7 using-explain", "sha256": "650fd8629382d5dc8f9f8412c50ec5f32442a9ad2f98ca88e5348a7c2bd0ac7a", "language": "en", "original_url": "/docs/13/using-explain.html#USING-EXPLAIN-BASICS"}, {"url": "https://pg.center/docs/13/using-explain.html#USING-EXPLAIN-ANALYZE", "path": "using-explain.html", "label": "PostgreSQL 13.23 \u00b7 using-explain", "sha256": "650fd8629382d5dc8f9f8412c50ec5f32442a9ad2f98ca88e5348a7c2bd0ac7a", "language": "en", "original_url": "/docs/13/using-explain.html#USING-EXPLAIN-ANALYZE"}], "node_tag": "T_BitmapAnd", "sections": [{"title": "EXPLAIN \u540d\u79f0\u4e0e\u5c5e\u6027", "paragraphs": ["\u7ed3\u6784\u5316\u683c\u5f0f\u4f7f\u7528\u4e0a\u8ff0 Node Type\u3002\u6587\u672c\u683c\u5f0f\u540d\u79f0\u8fd8\u53ef\u80fd\u5305\u542b\u64cd\u4f5c\u3001\u7b56\u7565\u3001\u8fde\u63a5\u7c7b\u578b\u3001\u626b\u63cf\u65b9\u5411\u6216\u805a\u5408\u9636\u6bb5\u5c5e\u6027\u3002", "\u6b64\u6e90\u7801\u8bb0\u5f55\u7684\u6587\u672c\u540d\u79f0\uff1aBitmapAnd.", "\u5e76\u884c\u611f\u77e5\u4e0e\u5e76\u884c\u5b89\u5168\u662f\u4e0d\u540c\u7684\u8ba1\u5212\u5c5e\u6027\u3002\u5728\u5e76\u884c\u5de5\u4f5c\u8fdb\u7a0b\u5185\u8fd0\u884c\u7684\u8282\u70b9\u4e0d\u4e00\u5b9a\u662f\u5e76\u884c\u611f\u77e5\u8282\u70b9\u3002"]}, {"title": "\u5185\u5b58\u4e0e\u4e34\u65f6\u5b58\u50a8", "paragraphs": ["\u672c\u6b21\u62bd\u53d6\u4e0d\u4e3a\u6b64\u8282\u70b9\u8bbe\u5b9a\u7edf\u4e00\u7684\u5185\u5b58\u4e0a\u9650\u6216\u843d\u76d8\u7b56\u7565\u3002\u8bf7\u67e5\u770b\u540c\u4e00\u6784\u5efa\u7684\u5b9e\u73b0\u3001\u76f8\u5173\u8868\u8fbe\u5f0f\u6216\u63d0\u4f9b\u65b9\u3002"]}, {"title": "\u5e76\u884c\u6267\u884c\u4e0e\u8fd0\u884c\u4fe1\u606f\u91c7\u96c6", "paragraphs": ["\u4ee5\u4e0b\u6e90\u7801\u56de\u8c03\u53ef\u4ee5\u534f\u8c03\u6267\u884c\u6216\u6536\u96c6\u5de5\u4f5c\u8fdb\u7a0b\u7684\u6d4b\u91cf\u6570\u636e\u3002\u56de\u8c03\u5b58\u5728\u4e0d\u4ee3\u8868\u8be5\u8282\u70b9\u666e\u904d\u652f\u6301\u5171\u4eab\u5e76\u884c\u626b\u63cf\u6216\u5171\u4eab\u72b6\u6001\u3002", "\u6b64\u6784\u5efa\u7684\u56de\u8c03\uff1anone extracted from this node implementation."]}, {"title": "\u540c\u7248\u672c\u624b\u518c\u8bf4\u660e", "paragraphs": ["\u7531\u4e8e\u5b9e\u73b0\u4e0a\u7684\u9650\u5236\uff0cBitmapAnd \u548c BitmapOr \u8282\u70b9\u62a5\u544a\u7684\u5b9e\u9645\u884c\u6570\u59cb\u7ec8\u4e3a\u96f6\u3002"]}, {"title": "\u672c\u7248\u624b\u518c\u4e2d\u7684\u793a\u4f8b", "blocks": [{"code": "EXPLAIN SELECT * FROM tenk1 WHERE unique1 < 100 AND unique2 > 9000;\n\n QUERY PLAN\n-------------------------------------------------------------------------------------\n Bitmap Heap Scan on tenk1 (cost=25.08..60.21 rows=10 width=244)\n Recheck Cond: ((unique1 < 100) AND (unique2 > 9000))\n -> BitmapAnd (cost=25.08..25.08 rows=10 width=0)\n -> Bitmap Index Scan on tenk1_unique1 (cost=0.00..5.04 rows=101 width=0)\n Index Cond: (unique1 < 100)\n -> Bitmap Index Scan on tenk1_unique2 (cost=0.00..19.78 rows=999 width=0)\n Index Cond: (unique2 > 9000)", "source": {"url": "/docs/13/using-explain.html#USING-EXPLAIN-BASICS", "path": "using-explain.html", "label": "PostgreSQL 13.23 \u00b7 using-explain", "sha256": "650fd8629382d5dc8f9f8412c50ec5f32442a9ad2f98ca88e5348a7c2bd0ac7a"}, "paragraphs": ["\u793a\u4f8b\u6458\u81ea PostgreSQL 13.23 \u624b\u518c\uff1b\u672c\u767e\u79d1\u672a\u5b9e\u9645\u6267\u884c\u6b64\u793a\u4f8b\u3002", "\u5982\u679c WHERE \u5f15\u7528\u7684\u591a\u4e2a\u5217\u4e0a\u5206\u522b\u5efa\u6709\u7d22\u5f15\uff0c\u89c4\u5212\u5668\u53ef\u80fd\u9009\u62e9\u7528 AND \u6216 OR \u7ec4\u5408\u8fd9\u4e9b\u7d22\u5f15\uff1a"]}, {"code": "EXPLAIN (ANALYZE, BUFFERS) SELECT * FROM tenk1 WHERE unique1 < 100 AND unique2 > 9000;\n\n QUERY PLAN\n---------------------------------------------------------------------------------------------------------------------------------\n Bitmap Heap Scan on tenk1 (cost=25.08..60.21 rows=10 width=244) (actual time=0.323..0.342 rows=10 loops=1)\n Recheck Cond: ((unique1 < 100) AND (unique2 > 9000))\n Buffers: shared hit=15\n -> BitmapAnd (cost=25.08..25.08 rows=10 width=0) (actual time=0.309..0.309 rows=0 loops=1)\n Buffers: shared hit=7\n -> Bitmap Index Scan on tenk1_unique1 (cost=0.00..5.04 rows=101 width=0) (actual time=0.043..0.043 rows=100 loops=1)\n Index Cond: (unique1 < 100)\n Buffers: shared hit=2\n -> Bitmap Index Scan on tenk1_unique2 (cost=0.00..19.78 rows=999 width=0) (actual time=0.227..0.227 rows=999 loops=1)\n Index Cond: (unique2 > 9000)\n Buffers: shared hit=5\n Planning time: 0.088 ms\n Execution time: 0.423 ms", "source": {"url": "/docs/13/using-explain.html#USING-EXPLAIN-ANALYZE", "path": "using-explain.html", "label": "PostgreSQL 13.23 \u00b7 using-explain", "sha256": "650fd8629382d5dc8f9f8412c50ec5f32442a9ad2f98ca88e5348a7c2bd0ac7a"}, "paragraphs": ["\u793a\u4f8b\u6458\u81ea PostgreSQL 13.23 \u624b\u518c\uff1b\u672c\u767e\u79d1\u672a\u5b9e\u9645\u6267\u884c\u6b64\u793a\u4f8b\u3002", "EXPLAIN \u7684 BUFFERS \u9009\u9879\u53ef\u4e0e ANALYZE \u914d\u5408\u4f7f\u7528\uff0c\u4ee5\u83b7\u53d6\u66f4\u591a\u8fd0\u884c\u65f6\u7edf\u8ba1\u4fe1\u606f\uff1a"]}]}, {"title": "\u6267\u884c\u5668\u5b9e\u73b0\u8bf4\u660e", "paragraphs": ["\u8bf4\u660e\uff1aBitmapAnd \u4e0d\u4f7f\u7528\u5de6\u53f3\u5b50\u6811\uff0c\u800c\u50cf Append \u4e00\u6837\u7ef4\u62a4\u5b50\u8ba1\u5212\u5217\u8868\u3002\u4e0d\u8fc7\u5176\u903b\u8f91\u6bd4 Append \u7b80\u5355\u5f97\u591a\uff0c\u56e0\u4e3a\u65e0\u9700\u5904\u7406\u6b63\u5411\u6216\u53cd\u5411\u6267\u884c\u3002", "\u5bf9\u6bcf\u4e2a\u5f85\u6267\u884c\u8ba1\u5212\u8c03\u7528 ExecInitNode\uff0c\u5e76\u5c06\u7ed3\u679c\u4fdd\u5b58\u5230 bitmapplanstates \u6570\u7ec4\u3002", "BitmapAnd \u8ba1\u5212\u6ca1\u6709\u8868\u8fbe\u5f0f\u4e0a\u4e0b\u6587\uff0c\u56e0\u4e3a\u5b83\u4eec\u4ece\u4e0d\u8c03\u7528 ExecQual \u6216 ExecProject\uff0c\u4e5f\u4e0d\u9700\u8981\u5143\u7ec4\u69fd\u3002", "\u5982\u679c\u5728\u4efb\u4f55\u9636\u6bb5\u5f97\u5230\u5b8c\u5168\u4e3a\u7a7a\u7684\u4f4d\u56fe\uff0c\u5c31\u53ef\u4ee5\u76f4\u63a5\u9000\u51fa\uff0c\u65e0\u9700\u6267\u884c\u5269\u4f59\u5b50\u8ba1\u5212\uff0c\u56e0\u4e3a\u518d\u8fdb\u884c AND \u8fd0\u7b97\u4e5f\u4e0d\u4f1a\u6539\u53d8\u7ed3\u679c\u3002\uff08\u6ce8\u610f\uff1aindxpath.c \u6309\u9009\u62e9\u7387\u5bf9\u5b50\u8ba1\u5212\u6392\u5e8f\uff0c\u5e94\u5f53\u80fd\u63d0\u9ad8\u51fa\u73b0\u8fd9\u79cd\u60c5\u51b5\u7684\u6982\u7387\u3002\uff09", "ExecReScan \u4e0d\u77e5\u9053\u5f53\u524d\u8282\u70b9\u7684\u5b50\u8ba1\u5212\uff0c\u56e0\u6b64\u5fc5\u987b\u81ea\u884c\u901a\u77e5\u5b50\u8ba1\u5212\u54ea\u4e9b\u53c2\u6570\u53d1\u751f\u4e86\u53d8\u5316\u3002"]}, {"code": "case T_BitmapAnd:\n\t\t\tpname = sname = \"BitmapAnd\";\n\t\t\tbreak;", "title": "\u6838\u5fc3\u6e90\u7801\u4e2d\u7684 EXPLAIN \u6807\u8bc6"}], "strategies": [], "description": ["\u5bf9\u5404\u5b50\u8ba1\u5212\u4ea7\u751f\u7684\u4f4d\u56fe\u6c42\u4ea4\u96c6\u3002"], "localization": {"status": "complete", "sources": [], "language": "zh", "original_text": {"/versions/13/description/0": "Intersects bitmaps produced by its child plans.", "/versions/13/facts/0/label": "Core node tag", "/versions/13/facts/1/label": "Structured EXPLAIN Node Type", "/versions/13/facts/2/label": "Inputs", "/versions/13/facts/2/value": "Bitmap-producing child plans", "/versions/13/facts/3/label": "Output", "/versions/13/facts/3/value": "Tuple-location bitmap, not a tuple stream", "/versions/13/facts/4/label": "Executor initializer", "/versions/13/facts/5/label": "Memory mechanism", "/versions/13/tables/0/title": "EXPLAIN labels in this source build", "/versions/13/related/1/label": "Using EXPLAIN", "/versions/13/related/2/label": "Parallel plans", "/versions/13/sections/0/title": "EXPLAIN names and attributes", "/versions/13/sections/1/title": "Memory and temporary storage", "/versions/13/sections/2/title": "Parallel execution and instrumentation", "/versions/13/sections/3/title": "Same-version manual discussion", "/versions/13/sections/4/title": "Examples from this manual build", "/versions/13/sections/5/title": "Executor implementation notes", "/versions/13/sections/6/title": "EXPLAIN identity in core source", "/versions/13/memory/description": "This extraction does not assign a universal memory limit or spill policy to this node. Inspect the same-build implementation and its expressions or provider.", "/versions/13/sections/0/paragraphs/0": "Structured formats use the Node Type above. Text-format spellings can also include operation, strategy, join type, scan direction or aggregation-stage attributes.", "/versions/13/sections/0/paragraphs/1": "Text names recorded by this source: BitmapAnd.", "/versions/13/sections/0/paragraphs/2": "Parallel-aware and parallel-safe are different plan properties. A node running inside a parallel worker is not necessarily a parallel-aware node.", "/versions/13/sections/1/paragraphs/0": "This extraction does not assign a universal memory limit or spill policy to this node. Inspect the same-build implementation and its expressions or provider.", "/versions/13/sections/2/paragraphs/0": "The source callbacks below can coordinate execution or collect worker instrumentation. Their presence is not a blanket claim that this node supports a shared parallel scan or shared state.", "/versions/13/sections/2/paragraphs/1": "Callbacks in this build: none extracted from this node implementation.", "/versions/13/sections/3/paragraphs/0": "BitmapAnd and BitmapOr nodes always report their actual row counts as zero, due to implementation limitations.", "/versions/13/sections/5/paragraphs/0": "NOTES BitmapAnd nodes don't make use of their left and right subtrees, rather they maintain a list of subplans, much like Append nodes. The logic is much simpler than Append, however, since we needn't cope with forward/backward execution.", "/versions/13/sections/5/paragraphs/1": "call ExecInitNode on each of the plans to be executed and save the results into the array \"bitmapplanstates\".", "/versions/13/sections/5/paragraphs/2": "BitmapAnd plans don't have expression contexts because they never call ExecQual or ExecProject. They don't need any tuple slots either.", "/versions/13/sections/5/paragraphs/3": "If at any stage we have a completely empty bitmap, we can fall out without evaluating the remaining subplans, since ANDing them can no longer change the result. (Note: the fact that indxpath.c orders the subplans by selectivity should make this case more likely to occur.)", "/versions/13/sections/5/paragraphs/4": "ExecReScan doesn't know about my subplans, so I have to do changed-parameter signaling myself.", "/versions/13/tables/0/columns/0/label": "Text-format label", "/versions/13/tables/0/columns/1/label": "Structured node identity", "/versions/13/sections/4/blocks/0/paragraphs/0": "Example copied from the PostgreSQL 13.23 manual; it was not executed for this collection.", "/versions/13/sections/4/blocks/0/paragraphs/1": "If there are separate indexes on several of the columns referenced in WHERE , the planner might choose to use an AND or OR combination of the indexes:", "/versions/13/sections/4/blocks/1/paragraphs/0": "Example copied from the PostgreSQL 13.23 manual; it was not executed for this collection.", "/versions/13/sections/4/blocks/1/paragraphs/1": "EXPLAIN has a BUFFERS option that can be used with ANALYZE to get even more run time statistics:"}, "fallback_fields": [], "source_language": "en", "original_snapshot_sha256": "d6569830baf694b9306f6394cd1db1d4c61878ecef8a844d87401c124ab6b423"}, "evidence_kind": "source and documentation", "explain_names": ["BitmapAnd"], "partial_modes": [], "comparison_data": {"node_tag": "T_BitmapAnd", "strategies": [], "text_names": ["BitmapAnd"], "initializer": "ExecInitBitmapAnd", "partial_modes": [], "memory_mechanism": "unclassified", "parallel_callbacks": []}, "comparison_hash": "ffac2f4c3c78a9e2f88eb2c2de755f5a69e40f1ac6d7e9bcb4ed08615c9cb803", "explain_prefixes": ["Parallel"], "runtime_verified": false, "source_inventory": {"explain": "src/backend/commands/explain.c", "executor": "src/backend/executor/execProcnode.c", "implementation": "src/backend/executor/nodeBitmapAnd.c"}, "parallel_callbacks": []}, "14": {"facts": [{"label": "\u6838\u5fc3\u8282\u70b9\u6807\u7b7e", "value": "T_BitmapAnd"}, {"label": "\u7ed3\u6784\u5316 EXPLAIN \u8282\u70b9\u7c7b\u578b", "value": "BitmapAnd"}, {"label": "\u8f93\u5165", "value": "\u4ea7\u751f\u4f4d\u56fe\u7684\u5b50\u8ba1\u5212"}, {"label": "\u8f93\u51fa", "value": "\u5143\u7ec4\u4f4d\u7f6e\u4f4d\u56fe\uff0c\u4e0d\u662f\u5143\u7ec4\u6d41"}, {"label": "\u6267\u884c\u5668\u521d\u59cb\u5316\u51fd\u6570", "value": "ExecInitBitmapAnd"}, {"label": "\u5185\u5b58\u673a\u5236", "value": "unclassified"}], "memory": {"evidence": [{"url": "https://ftp.postgresql.org/pub/source/v14.24/postgresql-14.24.tar.bz2", "path": "src/backend/executor/nodeBitmapAnd.c", "label": "src/backend/executor/nodeBitmapAnd.c", "sha256": "c096e3ef00f28184fe4dd7f94a4c2930d37cf1d80f152665e28c011c86e92ab3", "archive_sha256": "a7fa7ed3d558172355f51406097a7bd4f6b473be80f311ef7cda96bf383d8897"}], "mechanism": "unclassified", "description": 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"src/backend/executor/nodeBitmapAnd.c", "label": "src/backend/executor/nodeBitmapAnd.c", "sha256": "c096e3ef00f28184fe4dd7f94a4c2930d37cf1d80f152665e28c011c86e92ab3", "archive_sha256": "a7fa7ed3d558172355f51406097a7bd4f6b473be80f311ef7cda96bf383d8897"}, {"url": "https://ftp.postgresql.org/pub/source/v14.24/postgresql-14.24.tar.bz2", "path": "src/include/nodes/plannodes.h", "label": "src/include/nodes/plannodes.h", "sha256": "302f51a16b570dba7ec4e7bc045f7df5800d21630280354d1a24025f3baec75d", "archive_sha256": "a7fa7ed3d558172355f51406097a7bd4f6b473be80f311ef7cda96bf383d8897"}, {"url": "https://pg.center/docs/14/using-explain.html#USING-EXPLAIN-CAVEATS", "path": "using-explain.html", "label": "PostgreSQL 14.24 \u00b7 using-explain", "sha256": "7f5ab59cb21a035ada45ea3426c5d1cca3f781273483677f73fdd76753555206", "language": "en", "original_url": "/docs/14/using-explain.html#USING-EXPLAIN-CAVEATS"}, {"url": "https://pg.center/docs/14/using-explain.html#USING-EXPLAIN-BASICS", "path": "using-explain.html", "label": "PostgreSQL 14.24 \u00b7 using-explain", "sha256": "7f5ab59cb21a035ada45ea3426c5d1cca3f781273483677f73fdd76753555206", "language": "en", "original_url": "/docs/14/using-explain.html#USING-EXPLAIN-BASICS"}, {"url": "https://pg.center/docs/14/using-explain.html#USING-EXPLAIN-ANALYZE", "path": "using-explain.html", "label": "PostgreSQL 14.24 \u00b7 using-explain", "sha256": "7f5ab59cb21a035ada45ea3426c5d1cca3f781273483677f73fdd76753555206", "language": "en", "original_url": "/docs/14/using-explain.html#USING-EXPLAIN-ANALYZE"}], "node_tag": "T_BitmapAnd", "sections": [{"title": "EXPLAIN \u540d\u79f0\u4e0e\u5c5e\u6027", "paragraphs": ["\u7ed3\u6784\u5316\u683c\u5f0f\u4f7f\u7528\u4e0a\u8ff0 Node Type\u3002\u6587\u672c\u683c\u5f0f\u540d\u79f0\u8fd8\u53ef\u80fd\u5305\u542b\u64cd\u4f5c\u3001\u7b56\u7565\u3001\u8fde\u63a5\u7c7b\u578b\u3001\u626b\u63cf\u65b9\u5411\u6216\u805a\u5408\u9636\u6bb5\u5c5e\u6027\u3002", "\u6b64\u6e90\u7801\u8bb0\u5f55\u7684\u6587\u672c\u540d\u79f0\uff1aBitmapAnd.", "\u5e76\u884c\u611f\u77e5\u4e0e\u5e76\u884c\u5b89\u5168\u662f\u4e0d\u540c\u7684\u8ba1\u5212\u5c5e\u6027\u3002\u5728\u5e76\u884c\u5de5\u4f5c\u8fdb\u7a0b\u5185\u8fd0\u884c\u7684\u8282\u70b9\u4e0d\u4e00\u5b9a\u662f\u5e76\u884c\u611f\u77e5\u8282\u70b9\u3002"]}, {"title": "\u5185\u5b58\u4e0e\u4e34\u65f6\u5b58\u50a8", "paragraphs": ["\u672c\u6b21\u62bd\u53d6\u4e0d\u4e3a\u6b64\u8282\u70b9\u8bbe\u5b9a\u7edf\u4e00\u7684\u5185\u5b58\u4e0a\u9650\u6216\u843d\u76d8\u7b56\u7565\u3002\u8bf7\u67e5\u770b\u540c\u4e00\u6784\u5efa\u7684\u5b9e\u73b0\u3001\u76f8\u5173\u8868\u8fbe\u5f0f\u6216\u63d0\u4f9b\u65b9\u3002"]}, {"title": "\u5e76\u884c\u6267\u884c\u4e0e\u8fd0\u884c\u4fe1\u606f\u91c7\u96c6", "paragraphs": ["\u4ee5\u4e0b\u6e90\u7801\u56de\u8c03\u53ef\u4ee5\u534f\u8c03\u6267\u884c\u6216\u6536\u96c6\u5de5\u4f5c\u8fdb\u7a0b\u7684\u6d4b\u91cf\u6570\u636e\u3002\u56de\u8c03\u5b58\u5728\u4e0d\u4ee3\u8868\u8be5\u8282\u70b9\u666e\u904d\u652f\u6301\u5171\u4eab\u5e76\u884c\u626b\u63cf\u6216\u5171\u4eab\u72b6\u6001\u3002", "\u6b64\u6784\u5efa\u7684\u56de\u8c03\uff1anone extracted from this node implementation."]}, {"title": "\u540c\u7248\u672c\u624b\u518c\u8bf4\u660e", "paragraphs": ["\u7531\u4e8e\u5b9e\u73b0\u4e0a\u7684\u9650\u5236\uff0cBitmapAnd \u548c BitmapOr \u8282\u70b9\u62a5\u544a\u7684\u5b9e\u9645\u884c\u6570\u59cb\u7ec8\u4e3a\u96f6\u3002"]}, {"title": "\u672c\u7248\u624b\u518c\u4e2d\u7684\u793a\u4f8b", "blocks": [{"code": "EXPLAIN SELECT * FROM tenk1 WHERE unique1 < 100 AND unique2 > 9000;\n\n QUERY PLAN\n-------------------------------------------------------------------------------------\n Bitmap Heap Scan on tenk1 (cost=25.08..60.21 rows=10 width=244)\n Recheck Cond: ((unique1 < 100) AND (unique2 > 9000))\n -> BitmapAnd (cost=25.08..25.08 rows=10 width=0)\n -> Bitmap Index Scan on tenk1_unique1 (cost=0.00..5.04 rows=101 width=0)\n Index Cond: (unique1 < 100)\n -> Bitmap Index Scan on tenk1_unique2 (cost=0.00..19.78 rows=999 width=0)\n Index Cond: (unique2 > 9000)", "source": {"url": "/docs/14/using-explain.html#USING-EXPLAIN-BASICS", "path": "using-explain.html", "label": "PostgreSQL 14.24 \u00b7 using-explain", "sha256": "7f5ab59cb21a035ada45ea3426c5d1cca3f781273483677f73fdd76753555206"}, "paragraphs": ["\u793a\u4f8b\u6458\u81ea PostgreSQL 14.24 \u624b\u518c\uff1b\u672c\u767e\u79d1\u672a\u5b9e\u9645\u6267\u884c\u6b64\u793a\u4f8b\u3002", "\u5982\u679c WHERE \u5f15\u7528\u7684\u591a\u4e2a\u5217\u4e0a\u5206\u522b\u5efa\u6709\u7d22\u5f15\uff0c\u89c4\u5212\u5668\u53ef\u80fd\u9009\u62e9\u7528 AND \u6216 OR \u7ec4\u5408\u8fd9\u4e9b\u7d22\u5f15\uff1a"]}, {"code": "EXPLAIN (ANALYZE, BUFFERS) SELECT * FROM tenk1 WHERE unique1 < 100 AND unique2 > 9000;\n\n QUERY PLAN\n---------------------------------------------------------------------------------------------------------------------------------\n Bitmap Heap Scan on tenk1 (cost=25.08..60.21 rows=10 width=244) (actual time=0.323..0.342 rows=10 loops=1)\n Recheck Cond: ((unique1 < 100) AND (unique2 > 9000))\n Buffers: shared hit=15\n -> BitmapAnd (cost=25.08..25.08 rows=10 width=0) (actual time=0.309..0.309 rows=0 loops=1)\n Buffers: shared hit=7\n -> Bitmap Index Scan on tenk1_unique1 (cost=0.00..5.04 rows=101 width=0) (actual time=0.043..0.043 rows=100 loops=1)\n Index Cond: (unique1 < 100)\n Buffers: shared hit=2\n -> Bitmap Index Scan on tenk1_unique2 (cost=0.00..19.78 rows=999 width=0) (actual time=0.227..0.227 rows=999 loops=1)\n Index Cond: (unique2 > 9000)\n Buffers: shared hit=5\n Planning time: 0.088 ms\n Execution time: 0.423 ms", "source": {"url": "/docs/14/using-explain.html#USING-EXPLAIN-ANALYZE", "path": "using-explain.html", "label": "PostgreSQL 14.24 \u00b7 using-explain", "sha256": "7f5ab59cb21a035ada45ea3426c5d1cca3f781273483677f73fdd76753555206"}, "paragraphs": ["\u793a\u4f8b\u6458\u81ea PostgreSQL 14.24 \u624b\u518c\uff1b\u672c\u767e\u79d1\u672a\u5b9e\u9645\u6267\u884c\u6b64\u793a\u4f8b\u3002", "EXPLAIN \u7684 BUFFERS \u9009\u9879\u53ef\u4e0e ANALYZE \u914d\u5408\u4f7f\u7528\uff0c\u4ee5\u83b7\u53d6\u66f4\u591a\u8fd0\u884c\u65f6\u7edf\u8ba1\u4fe1\u606f\uff1a"]}]}, {"title": "\u6267\u884c\u5668\u5b9e\u73b0\u8bf4\u660e", "paragraphs": ["\u8bf4\u660e\uff1aBitmapAnd \u4e0d\u4f7f\u7528\u5de6\u53f3\u5b50\u6811\uff0c\u800c\u50cf Append \u4e00\u6837\u7ef4\u62a4\u5b50\u8ba1\u5212\u5217\u8868\u3002\u4e0d\u8fc7\u5176\u903b\u8f91\u6bd4 Append \u7b80\u5355\u5f97\u591a\uff0c\u56e0\u4e3a\u65e0\u9700\u5904\u7406\u6b63\u5411\u6216\u53cd\u5411\u6267\u884c\u3002", "\u5bf9\u6bcf\u4e2a\u5f85\u6267\u884c\u8ba1\u5212\u8c03\u7528 ExecInitNode\uff0c\u5e76\u5c06\u7ed3\u679c\u4fdd\u5b58\u5230 bitmapplanstates \u6570\u7ec4\u3002", "BitmapAnd \u8ba1\u5212\u6ca1\u6709\u8868\u8fbe\u5f0f\u4e0a\u4e0b\u6587\uff0c\u56e0\u4e3a\u5b83\u4eec\u4ece\u4e0d\u8c03\u7528 ExecQual \u6216 ExecProject\uff0c\u4e5f\u4e0d\u9700\u8981\u5143\u7ec4\u69fd\u3002", "\u5982\u679c\u5728\u4efb\u4f55\u9636\u6bb5\u5f97\u5230\u5b8c\u5168\u4e3a\u7a7a\u7684\u4f4d\u56fe\uff0c\u5c31\u53ef\u4ee5\u76f4\u63a5\u9000\u51fa\uff0c\u65e0\u9700\u6267\u884c\u5269\u4f59\u5b50\u8ba1\u5212\uff0c\u56e0\u4e3a\u518d\u8fdb\u884c AND \u8fd0\u7b97\u4e5f\u4e0d\u4f1a\u6539\u53d8\u7ed3\u679c\u3002\uff08\u6ce8\u610f\uff1aindxpath.c \u6309\u9009\u62e9\u7387\u5bf9\u5b50\u8ba1\u5212\u6392\u5e8f\uff0c\u5e94\u5f53\u80fd\u63d0\u9ad8\u51fa\u73b0\u8fd9\u79cd\u60c5\u51b5\u7684\u6982\u7387\u3002\uff09", "ExecReScan \u4e0d\u77e5\u9053\u5f53\u524d\u8282\u70b9\u7684\u5b50\u8ba1\u5212\uff0c\u56e0\u6b64\u5fc5\u987b\u81ea\u884c\u901a\u77e5\u5b50\u8ba1\u5212\u54ea\u4e9b\u53c2\u6570\u53d1\u751f\u4e86\u53d8\u5316\u3002"]}, {"code": "case T_BitmapAnd:\n\t\t\tpname = sname = \"BitmapAnd\";\n\t\t\tbreak;", "title": "\u6838\u5fc3\u6e90\u7801\u4e2d\u7684 EXPLAIN \u6807\u8bc6"}], "strategies": [], "description": ["\u5bf9\u5404\u5b50\u8ba1\u5212\u4ea7\u751f\u7684\u4f4d\u56fe\u6c42\u4ea4\u96c6\u3002"], "localization": {"status": "complete", "sources": [], "language": "zh", "original_text": {"/versions/14/description/0": "Intersects bitmaps produced by its child plans.", "/versions/14/facts/0/label": "Core node tag", "/versions/14/facts/1/label": "Structured EXPLAIN Node Type", "/versions/14/facts/2/label": "Inputs", "/versions/14/facts/2/value": "Bitmap-producing child plans", "/versions/14/facts/3/label": "Output", "/versions/14/facts/3/value": "Tuple-location bitmap, not a tuple stream", "/versions/14/facts/4/label": "Executor initializer", "/versions/14/facts/5/label": "Memory mechanism", "/versions/14/tables/0/title": "EXPLAIN labels in this source build", "/versions/14/related/1/label": "Using EXPLAIN", "/versions/14/related/2/label": "Parallel plans", "/versions/14/sections/0/title": "EXPLAIN names and attributes", "/versions/14/sections/1/title": "Memory and temporary storage", "/versions/14/sections/2/title": "Parallel execution and instrumentation", "/versions/14/sections/3/title": "Same-version manual discussion", "/versions/14/sections/4/title": "Examples from this manual build", "/versions/14/sections/5/title": "Executor implementation notes", "/versions/14/sections/6/title": "EXPLAIN identity in core source", "/versions/14/memory/description": "This extraction does not assign a universal memory limit or spill policy to this node. Inspect the same-build implementation and its expressions or provider.", "/versions/14/sections/0/paragraphs/0": "Structured formats use the Node Type above. Text-format spellings can also include operation, strategy, join type, scan direction or aggregation-stage attributes.", "/versions/14/sections/0/paragraphs/1": "Text names recorded by this source: BitmapAnd.", "/versions/14/sections/0/paragraphs/2": "Parallel-aware and parallel-safe are different plan properties. A node running inside a parallel worker is not necessarily a parallel-aware node.", "/versions/14/sections/1/paragraphs/0": "This extraction does not assign a universal memory limit or spill policy to this node. Inspect the same-build implementation and its expressions or provider.", "/versions/14/sections/2/paragraphs/0": "The source callbacks below can coordinate execution or collect worker instrumentation. Their presence is not a blanket claim that this node supports a shared parallel scan or shared state.", "/versions/14/sections/2/paragraphs/1": "Callbacks in this build: none extracted from this node implementation.", "/versions/14/sections/3/paragraphs/0": "BitmapAnd and BitmapOr nodes always report their actual row counts as zero, due to implementation limitations.", "/versions/14/sections/5/paragraphs/0": "NOTES BitmapAnd nodes don't make use of their left and right subtrees, rather they maintain a list of subplans, much like Append nodes. The logic is much simpler than Append, however, since we needn't cope with forward/backward execution.", "/versions/14/sections/5/paragraphs/1": "call ExecInitNode on each of the plans to be executed and save the results into the array \"bitmapplanstates\".", "/versions/14/sections/5/paragraphs/2": "BitmapAnd plans don't have expression contexts because they never call ExecQual or ExecProject. They don't need any tuple slots either.", "/versions/14/sections/5/paragraphs/3": "If at any stage we have a completely empty bitmap, we can fall out without evaluating the remaining subplans, since ANDing them can no longer change the result. (Note: the fact that indxpath.c orders the subplans by selectivity should make this case more likely to occur.)", "/versions/14/sections/5/paragraphs/4": "ExecReScan doesn't know about my subplans, so I have to do changed-parameter signaling myself.", "/versions/14/tables/0/columns/0/label": "Text-format label", "/versions/14/tables/0/columns/1/label": "Structured node identity", "/versions/14/sections/4/blocks/0/paragraphs/0": "Example copied from the PostgreSQL 14.24 manual; it was not executed for this collection.", "/versions/14/sections/4/blocks/0/paragraphs/1": "If there are separate indexes on several of the columns referenced in WHERE , the planner might choose to use an AND or OR combination of the indexes:", "/versions/14/sections/4/blocks/1/paragraphs/0": "Example copied from the PostgreSQL 14.24 manual; it was not executed for this collection.", "/versions/14/sections/4/blocks/1/paragraphs/1": "EXPLAIN has a BUFFERS option that can be used with ANALYZE to get even more run time statistics:"}, "fallback_fields": [], "source_language": "en", "original_snapshot_sha256": "fb3ae9c917ccdbf3fd1d6caf258d2f28e56249d169bbf593134dd3bf967bdcb6"}, "evidence_kind": "source and documentation", "explain_names": ["BitmapAnd"], "partial_modes": [], "comparison_data": {"node_tag": "T_BitmapAnd", "strategies": [], "text_names": ["BitmapAnd"], "initializer": "ExecInitBitmapAnd", "partial_modes": [], "memory_mechanism": "unclassified", "parallel_callbacks": []}, "comparison_hash": "ffac2f4c3c78a9e2f88eb2c2de755f5a69e40f1ac6d7e9bcb4ed08615c9cb803", "explain_prefixes": ["Parallel", "Async"], "runtime_verified": false, "source_inventory": {"explain": "src/backend/commands/explain.c", "executor": "src/backend/executor/execProcnode.c", "implementation": "src/backend/executor/nodeBitmapAnd.c"}, "parallel_callbacks": []}, "15": {"facts": [{"label": "\u6838\u5fc3\u8282\u70b9\u6807\u7b7e", "value": "T_BitmapAnd"}, {"label": "\u7ed3\u6784\u5316 EXPLAIN \u8282\u70b9\u7c7b\u578b", "value": "BitmapAnd"}, {"label": "\u8f93\u5165", "value": "\u4ea7\u751f\u4f4d\u56fe\u7684\u5b50\u8ba1\u5212"}, {"label": "\u8f93\u51fa", "value": "\u5143\u7ec4\u4f4d\u7f6e\u4f4d\u56fe\uff0c\u4e0d\u662f\u5143\u7ec4\u6d41"}, {"label": "\u6267\u884c\u5668\u521d\u59cb\u5316\u51fd\u6570", "value": "ExecInitBitmapAnd"}, {"label": "\u5185\u5b58\u673a\u5236", "value": "unclassified"}], "memory": {"evidence": [{"url": "https://ftp.postgresql.org/pub/source/v15.19/postgresql-15.19.tar.bz2", "path": "src/backend/executor/nodeBitmapAnd.c", "label": "src/backend/executor/nodeBitmapAnd.c", "sha256": "a68b2653499eda3a5c69d542314bf4dce813be2dfd4a0d09f547ec01085bcf08", "archive_sha256": "e1a64a87a46b825b88c082e4518161a47aab53c45694964f8ba1df28f7859f89"}], "mechanism": "unclassified", "description": 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"src/backend/executor/nodeBitmapAnd.c", "label": "src/backend/executor/nodeBitmapAnd.c", "sha256": "a68b2653499eda3a5c69d542314bf4dce813be2dfd4a0d09f547ec01085bcf08", "archive_sha256": "e1a64a87a46b825b88c082e4518161a47aab53c45694964f8ba1df28f7859f89"}, {"url": "https://ftp.postgresql.org/pub/source/v15.19/postgresql-15.19.tar.bz2", "path": "src/include/nodes/plannodes.h", "label": "src/include/nodes/plannodes.h", "sha256": "fb4a4c8165495299131173680bc02a950d88e1ff610231fd97997bc0c9afc1d7", "archive_sha256": "e1a64a87a46b825b88c082e4518161a47aab53c45694964f8ba1df28f7859f89"}, {"url": "https://pg.center/docs/15/using-explain.html#USING-EXPLAIN-CAVEATS", "path": "using-explain.html", "label": "PostgreSQL 15.19 \u00b7 using-explain", "sha256": "d1f509457c647da453d2575c772d91022a0f115dd84f9a3b20f5ff25a243648f", "language": "en", "original_url": "/docs/15/using-explain.html#USING-EXPLAIN-CAVEATS"}, {"url": "https://pg.center/docs/15/using-explain.html#USING-EXPLAIN-BASICS", "path": "using-explain.html", "label": "PostgreSQL 15.19 \u00b7 using-explain", "sha256": "d1f509457c647da453d2575c772d91022a0f115dd84f9a3b20f5ff25a243648f", "language": "en", "original_url": "/docs/15/using-explain.html#USING-EXPLAIN-BASICS"}, {"url": "https://pg.center/docs/15/using-explain.html#USING-EXPLAIN-ANALYZE", "path": "using-explain.html", "label": "PostgreSQL 15.19 \u00b7 using-explain", "sha256": "d1f509457c647da453d2575c772d91022a0f115dd84f9a3b20f5ff25a243648f", "language": "en", "original_url": "/docs/15/using-explain.html#USING-EXPLAIN-ANALYZE"}], "node_tag": "T_BitmapAnd", "sections": [{"title": "EXPLAIN \u540d\u79f0\u4e0e\u5c5e\u6027", "paragraphs": ["\u7ed3\u6784\u5316\u683c\u5f0f\u4f7f\u7528\u4e0a\u8ff0 Node Type\u3002\u6587\u672c\u683c\u5f0f\u540d\u79f0\u8fd8\u53ef\u80fd\u5305\u542b\u64cd\u4f5c\u3001\u7b56\u7565\u3001\u8fde\u63a5\u7c7b\u578b\u3001\u626b\u63cf\u65b9\u5411\u6216\u805a\u5408\u9636\u6bb5\u5c5e\u6027\u3002", "\u6b64\u6e90\u7801\u8bb0\u5f55\u7684\u6587\u672c\u540d\u79f0\uff1aBitmapAnd.", "\u5e76\u884c\u611f\u77e5\u4e0e\u5e76\u884c\u5b89\u5168\u662f\u4e0d\u540c\u7684\u8ba1\u5212\u5c5e\u6027\u3002\u5728\u5e76\u884c\u5de5\u4f5c\u8fdb\u7a0b\u5185\u8fd0\u884c\u7684\u8282\u70b9\u4e0d\u4e00\u5b9a\u662f\u5e76\u884c\u611f\u77e5\u8282\u70b9\u3002"]}, {"title": "\u5185\u5b58\u4e0e\u4e34\u65f6\u5b58\u50a8", "paragraphs": ["\u672c\u6b21\u62bd\u53d6\u4e0d\u4e3a\u6b64\u8282\u70b9\u8bbe\u5b9a\u7edf\u4e00\u7684\u5185\u5b58\u4e0a\u9650\u6216\u843d\u76d8\u7b56\u7565\u3002\u8bf7\u67e5\u770b\u540c\u4e00\u6784\u5efa\u7684\u5b9e\u73b0\u3001\u76f8\u5173\u8868\u8fbe\u5f0f\u6216\u63d0\u4f9b\u65b9\u3002"]}, {"title": "\u5e76\u884c\u6267\u884c\u4e0e\u8fd0\u884c\u4fe1\u606f\u91c7\u96c6", "paragraphs": ["\u4ee5\u4e0b\u6e90\u7801\u56de\u8c03\u53ef\u4ee5\u534f\u8c03\u6267\u884c\u6216\u6536\u96c6\u5de5\u4f5c\u8fdb\u7a0b\u7684\u6d4b\u91cf\u6570\u636e\u3002\u56de\u8c03\u5b58\u5728\u4e0d\u4ee3\u8868\u8be5\u8282\u70b9\u666e\u904d\u652f\u6301\u5171\u4eab\u5e76\u884c\u626b\u63cf\u6216\u5171\u4eab\u72b6\u6001\u3002", "\u6b64\u6784\u5efa\u7684\u56de\u8c03\uff1anone extracted from this node implementation."]}, {"title": "\u540c\u7248\u672c\u624b\u518c\u8bf4\u660e", "paragraphs": ["\u7531\u4e8e\u5b9e\u73b0\u4e0a\u7684\u9650\u5236\uff0cBitmapAnd \u548c BitmapOr \u8282\u70b9\u62a5\u544a\u7684\u5b9e\u9645\u884c\u6570\u59cb\u7ec8\u4e3a\u96f6\u3002"]}, {"title": "\u672c\u7248\u624b\u518c\u4e2d\u7684\u793a\u4f8b", "blocks": [{"code": "EXPLAIN SELECT * FROM tenk1 WHERE unique1 < 100 AND unique2 > 9000;\n\n QUERY PLAN\n-------------------------------------------------------------------------------------\n Bitmap Heap Scan on tenk1 (cost=25.08..60.21 rows=10 width=244)\n Recheck Cond: ((unique1 < 100) AND (unique2 > 9000))\n -> BitmapAnd (cost=25.08..25.08 rows=10 width=0)\n -> Bitmap Index Scan on tenk1_unique1 (cost=0.00..5.04 rows=101 width=0)\n Index Cond: (unique1 < 100)\n -> Bitmap Index Scan on tenk1_unique2 (cost=0.00..19.78 rows=999 width=0)\n Index Cond: (unique2 > 9000)", "source": {"url": "/docs/15/using-explain.html#USING-EXPLAIN-BASICS", "path": "using-explain.html", "label": "PostgreSQL 15.19 \u00b7 using-explain", "sha256": "d1f509457c647da453d2575c772d91022a0f115dd84f9a3b20f5ff25a243648f"}, "paragraphs": ["\u793a\u4f8b\u6458\u81ea PostgreSQL 15.19 \u624b\u518c\uff1b\u672c\u767e\u79d1\u672a\u5b9e\u9645\u6267\u884c\u6b64\u793a\u4f8b\u3002", "\u5982\u679c WHERE \u5f15\u7528\u7684\u591a\u4e2a\u5217\u4e0a\u5206\u522b\u5efa\u6709\u7d22\u5f15\uff0c\u89c4\u5212\u5668\u53ef\u80fd\u9009\u62e9\u7528 AND \u6216 OR \u7ec4\u5408\u8fd9\u4e9b\u7d22\u5f15\uff1a"]}, {"code": "EXPLAIN (ANALYZE, BUFFERS) SELECT * FROM tenk1 WHERE unique1 < 100 AND unique2 > 9000;\n\n QUERY PLAN\n---------------------------------------------------------------------------------------------------------------------------------\n Bitmap Heap Scan on tenk1 (cost=25.08..60.21 rows=10 width=244) (actual time=0.323..0.342 rows=10 loops=1)\n Recheck Cond: ((unique1 < 100) AND (unique2 > 9000))\n Buffers: shared hit=15\n -> BitmapAnd (cost=25.08..25.08 rows=10 width=0) (actual time=0.309..0.309 rows=0 loops=1)\n Buffers: shared hit=7\n -> Bitmap Index Scan on tenk1_unique1 (cost=0.00..5.04 rows=101 width=0) (actual time=0.043..0.043 rows=100 loops=1)\n Index Cond: (unique1 < 100)\n Buffers: shared hit=2\n -> Bitmap Index Scan on tenk1_unique2 (cost=0.00..19.78 rows=999 width=0) (actual time=0.227..0.227 rows=999 loops=1)\n Index Cond: (unique2 > 9000)\n Buffers: shared hit=5\n Planning time: 0.088 ms\n Execution time: 0.423 ms", "source": {"url": "/docs/15/using-explain.html#USING-EXPLAIN-ANALYZE", "path": "using-explain.html", "label": "PostgreSQL 15.19 \u00b7 using-explain", "sha256": "d1f509457c647da453d2575c772d91022a0f115dd84f9a3b20f5ff25a243648f"}, "paragraphs": ["\u793a\u4f8b\u6458\u81ea PostgreSQL 15.19 \u624b\u518c\uff1b\u672c\u767e\u79d1\u672a\u5b9e\u9645\u6267\u884c\u6b64\u793a\u4f8b\u3002", "EXPLAIN \u7684 BUFFERS \u9009\u9879\u53ef\u4e0e ANALYZE \u914d\u5408\u4f7f\u7528\uff0c\u4ee5\u83b7\u53d6\u66f4\u591a\u8fd0\u884c\u65f6\u7edf\u8ba1\u4fe1\u606f\uff1a"]}]}, {"title": "\u6267\u884c\u5668\u5b9e\u73b0\u8bf4\u660e", "paragraphs": ["\u8bf4\u660e\uff1aBitmapAnd \u4e0d\u4f7f\u7528\u5de6\u53f3\u5b50\u6811\uff0c\u800c\u50cf Append \u4e00\u6837\u7ef4\u62a4\u5b50\u8ba1\u5212\u5217\u8868\u3002\u4e0d\u8fc7\u5176\u903b\u8f91\u6bd4 Append \u7b80\u5355\u5f97\u591a\uff0c\u56e0\u4e3a\u65e0\u9700\u5904\u7406\u6b63\u5411\u6216\u53cd\u5411\u6267\u884c\u3002", "\u5bf9\u6bcf\u4e2a\u5f85\u6267\u884c\u8ba1\u5212\u8c03\u7528 ExecInitNode\uff0c\u5e76\u5c06\u7ed3\u679c\u4fdd\u5b58\u5230 bitmapplanstates \u6570\u7ec4\u3002", "BitmapAnd \u8ba1\u5212\u6ca1\u6709\u8868\u8fbe\u5f0f\u4e0a\u4e0b\u6587\uff0c\u56e0\u4e3a\u5b83\u4eec\u4ece\u4e0d\u8c03\u7528 ExecQual \u6216 ExecProject\uff0c\u4e5f\u4e0d\u9700\u8981\u5143\u7ec4\u69fd\u3002", "\u5982\u679c\u5728\u4efb\u4f55\u9636\u6bb5\u5f97\u5230\u5b8c\u5168\u4e3a\u7a7a\u7684\u4f4d\u56fe\uff0c\u5c31\u53ef\u4ee5\u76f4\u63a5\u9000\u51fa\uff0c\u65e0\u9700\u6267\u884c\u5269\u4f59\u5b50\u8ba1\u5212\uff0c\u56e0\u4e3a\u518d\u8fdb\u884c AND \u8fd0\u7b97\u4e5f\u4e0d\u4f1a\u6539\u53d8\u7ed3\u679c\u3002\uff08\u6ce8\u610f\uff1aindxpath.c \u6309\u9009\u62e9\u7387\u5bf9\u5b50\u8ba1\u5212\u6392\u5e8f\uff0c\u5e94\u5f53\u80fd\u63d0\u9ad8\u51fa\u73b0\u8fd9\u79cd\u60c5\u51b5\u7684\u6982\u7387\u3002\uff09", "ExecReScan \u4e0d\u77e5\u9053\u5f53\u524d\u8282\u70b9\u7684\u5b50\u8ba1\u5212\uff0c\u56e0\u6b64\u5fc5\u987b\u81ea\u884c\u901a\u77e5\u5b50\u8ba1\u5212\u54ea\u4e9b\u53c2\u6570\u53d1\u751f\u4e86\u53d8\u5316\u3002"]}, {"code": "case T_BitmapAnd:\n\t\t\tpname = sname = \"BitmapAnd\";\n\t\t\tbreak;", "title": "\u6838\u5fc3\u6e90\u7801\u4e2d\u7684 EXPLAIN \u6807\u8bc6"}], "strategies": [], "description": ["\u5bf9\u5404\u5b50\u8ba1\u5212\u4ea7\u751f\u7684\u4f4d\u56fe\u6c42\u4ea4\u96c6\u3002"], "localization": {"status": "complete", "sources": [], "language": "zh", "original_text": {"/versions/15/description/0": "Intersects bitmaps produced by its child plans.", "/versions/15/facts/0/label": "Core node tag", "/versions/15/facts/1/label": "Structured EXPLAIN Node Type", "/versions/15/facts/2/label": "Inputs", "/versions/15/facts/2/value": "Bitmap-producing child plans", "/versions/15/facts/3/label": "Output", "/versions/15/facts/3/value": "Tuple-location bitmap, not a tuple stream", "/versions/15/facts/4/label": "Executor initializer", "/versions/15/facts/5/label": "Memory mechanism", "/versions/15/tables/0/title": "EXPLAIN labels in this source build", "/versions/15/related/1/label": "Using EXPLAIN", "/versions/15/related/2/label": "Parallel plans", "/versions/15/sections/0/title": "EXPLAIN names and attributes", "/versions/15/sections/1/title": "Memory and temporary storage", "/versions/15/sections/2/title": "Parallel execution and instrumentation", "/versions/15/sections/3/title": "Same-version manual discussion", "/versions/15/sections/4/title": "Examples from this manual build", "/versions/15/sections/5/title": "Executor implementation notes", "/versions/15/sections/6/title": "EXPLAIN identity in core source", "/versions/15/memory/description": "This extraction does not assign a universal memory limit or spill policy to this node. Inspect the same-build implementation and its expressions or provider.", "/versions/15/sections/0/paragraphs/0": "Structured formats use the Node Type above. Text-format spellings can also include operation, strategy, join type, scan direction or aggregation-stage attributes.", "/versions/15/sections/0/paragraphs/1": "Text names recorded by this source: BitmapAnd.", "/versions/15/sections/0/paragraphs/2": "Parallel-aware and parallel-safe are different plan properties. A node running inside a parallel worker is not necessarily a parallel-aware node.", "/versions/15/sections/1/paragraphs/0": "This extraction does not assign a universal memory limit or spill policy to this node. Inspect the same-build implementation and its expressions or provider.", "/versions/15/sections/2/paragraphs/0": "The source callbacks below can coordinate execution or collect worker instrumentation. Their presence is not a blanket claim that this node supports a shared parallel scan or shared state.", "/versions/15/sections/2/paragraphs/1": "Callbacks in this build: none extracted from this node implementation.", "/versions/15/sections/3/paragraphs/0": "BitmapAnd and BitmapOr nodes always report their actual row counts as zero, due to implementation limitations.", "/versions/15/sections/5/paragraphs/0": "NOTES BitmapAnd nodes don't make use of their left and right subtrees, rather they maintain a list of subplans, much like Append nodes. The logic is much simpler than Append, however, since we needn't cope with forward/backward execution.", "/versions/15/sections/5/paragraphs/1": "call ExecInitNode on each of the plans to be executed and save the results into the array \"bitmapplanstates\".", "/versions/15/sections/5/paragraphs/2": "BitmapAnd plans don't have expression contexts because they never call ExecQual or ExecProject. They don't need any tuple slots either.", "/versions/15/sections/5/paragraphs/3": "If at any stage we have a completely empty bitmap, we can fall out without evaluating the remaining subplans, since ANDing them can no longer change the result. (Note: the fact that indxpath.c orders the subplans by selectivity should make this case more likely to occur.)", "/versions/15/sections/5/paragraphs/4": "ExecReScan doesn't know about my subplans, so I have to do changed-parameter signaling myself.", "/versions/15/tables/0/columns/0/label": "Text-format label", "/versions/15/tables/0/columns/1/label": "Structured node identity", "/versions/15/sections/4/blocks/0/paragraphs/0": "Example copied from the PostgreSQL 15.19 manual; it was not executed for this collection.", "/versions/15/sections/4/blocks/0/paragraphs/1": "If there are separate indexes on several of the columns referenced in WHERE , the planner might choose to use an AND or OR combination of the indexes:", "/versions/15/sections/4/blocks/1/paragraphs/0": "Example copied from the PostgreSQL 15.19 manual; it was not executed for this collection.", "/versions/15/sections/4/blocks/1/paragraphs/1": "EXPLAIN has a BUFFERS option that can be used with ANALYZE to get even more run time statistics:"}, "fallback_fields": [], "source_language": "en", "original_snapshot_sha256": "b908919d80e10bd63dad238ac2d2d51dddefaa115f5e232058a46297d10ca03f"}, "evidence_kind": "source and documentation", "explain_names": ["BitmapAnd"], "partial_modes": [], "comparison_data": {"node_tag": "T_BitmapAnd", "strategies": [], "text_names": ["BitmapAnd"], "initializer": "ExecInitBitmapAnd", "partial_modes": [], "memory_mechanism": "unclassified", "parallel_callbacks": []}, "comparison_hash": "ffac2f4c3c78a9e2f88eb2c2de755f5a69e40f1ac6d7e9bcb4ed08615c9cb803", "explain_prefixes": ["Parallel", "Async"], "runtime_verified": false, "source_inventory": {"explain": "src/backend/commands/explain.c", "executor": "src/backend/executor/execProcnode.c", "implementation": "src/backend/executor/nodeBitmapAnd.c"}, "parallel_callbacks": []}, "16": {"facts": [{"label": "\u6838\u5fc3\u8282\u70b9\u6807\u7b7e", "value": "T_BitmapAnd"}, {"label": "\u7ed3\u6784\u5316 EXPLAIN \u8282\u70b9\u7c7b\u578b", "value": "BitmapAnd"}, {"label": "\u8f93\u5165", "value": "\u4ea7\u751f\u4f4d\u56fe\u7684\u5b50\u8ba1\u5212"}, {"label": "\u8f93\u51fa", "value": "\u5143\u7ec4\u4f4d\u7f6e\u4f4d\u56fe\uff0c\u4e0d\u662f\u5143\u7ec4\u6d41"}, {"label": "\u6267\u884c\u5668\u521d\u59cb\u5316\u51fd\u6570", "value": "ExecInitBitmapAnd"}, {"label": "\u5185\u5b58\u673a\u5236", "value": "unclassified"}], "memory": {"evidence": [{"url": "https://ftp.postgresql.org/pub/source/v16.15/postgresql-16.15.tar.bz2", "path": "src/backend/executor/nodeBitmapAnd.c", "label": "src/backend/executor/nodeBitmapAnd.c", "sha256": "c66658660763b50539da7d951c13c114cf83c26dc3c914e8a8f05844fc7271b0", "archive_sha256": "c1575341fa7bd40f5274ea465b34390f4dc64cdd0770af327005caaeb9f6b7ed"}], "mechanism": "unclassified", "description": 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"src/backend/executor/nodeBitmapAnd.c", "label": "src/backend/executor/nodeBitmapAnd.c", "sha256": "c66658660763b50539da7d951c13c114cf83c26dc3c914e8a8f05844fc7271b0", "archive_sha256": "c1575341fa7bd40f5274ea465b34390f4dc64cdd0770af327005caaeb9f6b7ed"}, {"url": "https://ftp.postgresql.org/pub/source/v16.15/postgresql-16.15.tar.bz2", "path": "src/include/nodes/plannodes.h", "label": "src/include/nodes/plannodes.h", "sha256": "97db47353db76326b874589a5ad0a04501cc74cd72e237e7bd956e7472c41f1f", "archive_sha256": "c1575341fa7bd40f5274ea465b34390f4dc64cdd0770af327005caaeb9f6b7ed"}, {"url": "https://pg.center/docs/16/using-explain.html#USING-EXPLAIN-CAVEATS", "path": "using-explain.html", "label": "PostgreSQL 16.15 \u00b7 using-explain", "sha256": "bd8b86e5281cf0e52ad6e0e4bb8b6ff6510dac61982b44f0c1dd07d54012db3c", "language": "en", "original_url": "/docs/16/using-explain.html#USING-EXPLAIN-CAVEATS"}, {"url": "https://pg.center/docs/16/using-explain.html#USING-EXPLAIN-BASICS", "path": "using-explain.html", "label": "PostgreSQL 16.15 \u00b7 using-explain", "sha256": "bd8b86e5281cf0e52ad6e0e4bb8b6ff6510dac61982b44f0c1dd07d54012db3c", "language": "en", "original_url": "/docs/16/using-explain.html#USING-EXPLAIN-BASICS"}, {"url": "https://pg.center/docs/16/using-explain.html#USING-EXPLAIN-ANALYZE", "path": "using-explain.html", "label": "PostgreSQL 16.15 \u00b7 using-explain", "sha256": "bd8b86e5281cf0e52ad6e0e4bb8b6ff6510dac61982b44f0c1dd07d54012db3c", "language": "en", "original_url": "/docs/16/using-explain.html#USING-EXPLAIN-ANALYZE"}], "node_tag": "T_BitmapAnd", "sections": [{"title": "EXPLAIN \u540d\u79f0\u4e0e\u5c5e\u6027", "paragraphs": ["\u7ed3\u6784\u5316\u683c\u5f0f\u4f7f\u7528\u4e0a\u8ff0 Node Type\u3002\u6587\u672c\u683c\u5f0f\u540d\u79f0\u8fd8\u53ef\u80fd\u5305\u542b\u64cd\u4f5c\u3001\u7b56\u7565\u3001\u8fde\u63a5\u7c7b\u578b\u3001\u626b\u63cf\u65b9\u5411\u6216\u805a\u5408\u9636\u6bb5\u5c5e\u6027\u3002", "\u6b64\u6e90\u7801\u8bb0\u5f55\u7684\u6587\u672c\u540d\u79f0\uff1aBitmapAnd.", "\u5e76\u884c\u611f\u77e5\u4e0e\u5e76\u884c\u5b89\u5168\u662f\u4e0d\u540c\u7684\u8ba1\u5212\u5c5e\u6027\u3002\u5728\u5e76\u884c\u5de5\u4f5c\u8fdb\u7a0b\u5185\u8fd0\u884c\u7684\u8282\u70b9\u4e0d\u4e00\u5b9a\u662f\u5e76\u884c\u611f\u77e5\u8282\u70b9\u3002"]}, {"title": "\u5185\u5b58\u4e0e\u4e34\u65f6\u5b58\u50a8", "paragraphs": ["\u672c\u6b21\u62bd\u53d6\u4e0d\u4e3a\u6b64\u8282\u70b9\u8bbe\u5b9a\u7edf\u4e00\u7684\u5185\u5b58\u4e0a\u9650\u6216\u843d\u76d8\u7b56\u7565\u3002\u8bf7\u67e5\u770b\u540c\u4e00\u6784\u5efa\u7684\u5b9e\u73b0\u3001\u76f8\u5173\u8868\u8fbe\u5f0f\u6216\u63d0\u4f9b\u65b9\u3002"]}, {"title": "\u5e76\u884c\u6267\u884c\u4e0e\u8fd0\u884c\u4fe1\u606f\u91c7\u96c6", "paragraphs": ["\u4ee5\u4e0b\u6e90\u7801\u56de\u8c03\u53ef\u4ee5\u534f\u8c03\u6267\u884c\u6216\u6536\u96c6\u5de5\u4f5c\u8fdb\u7a0b\u7684\u6d4b\u91cf\u6570\u636e\u3002\u56de\u8c03\u5b58\u5728\u4e0d\u4ee3\u8868\u8be5\u8282\u70b9\u666e\u904d\u652f\u6301\u5171\u4eab\u5e76\u884c\u626b\u63cf\u6216\u5171\u4eab\u72b6\u6001\u3002", "\u6b64\u6784\u5efa\u7684\u56de\u8c03\uff1anone extracted from this node implementation."]}, {"title": "\u540c\u7248\u672c\u624b\u518c\u8bf4\u660e", "paragraphs": ["\u7531\u4e8e\u5b9e\u73b0\u4e0a\u7684\u9650\u5236\uff0cBitmapAnd \u548c BitmapOr \u8282\u70b9\u62a5\u544a\u7684\u5b9e\u9645\u884c\u6570\u59cb\u7ec8\u4e3a\u96f6\u3002"]}, {"title": "\u672c\u7248\u624b\u518c\u4e2d\u7684\u793a\u4f8b", "blocks": [{"code": "EXPLAIN SELECT * FROM tenk1 WHERE unique1 < 100 AND unique2 > 9000;\n\n QUERY PLAN\n-------------------------------------------------------------------------------------\n Bitmap Heap Scan on tenk1 (cost=25.08..60.21 rows=10 width=244)\n Recheck Cond: ((unique1 < 100) AND (unique2 > 9000))\n -> BitmapAnd (cost=25.08..25.08 rows=10 width=0)\n -> Bitmap Index Scan on tenk1_unique1 (cost=0.00..5.04 rows=101 width=0)\n Index Cond: (unique1 < 100)\n -> Bitmap Index Scan on tenk1_unique2 (cost=0.00..19.78 rows=999 width=0)\n Index Cond: (unique2 > 9000)", "source": {"url": "/docs/16/using-explain.html#USING-EXPLAIN-BASICS", "path": "using-explain.html", "label": "PostgreSQL 16.15 \u00b7 using-explain", "sha256": "bd8b86e5281cf0e52ad6e0e4bb8b6ff6510dac61982b44f0c1dd07d54012db3c"}, "paragraphs": ["\u793a\u4f8b\u6458\u81ea PostgreSQL 16.15 \u624b\u518c\uff1b\u672c\u767e\u79d1\u672a\u5b9e\u9645\u6267\u884c\u6b64\u793a\u4f8b\u3002", "\u5982\u679c WHERE \u5f15\u7528\u7684\u591a\u4e2a\u5217\u4e0a\u5206\u522b\u5efa\u6709\u7d22\u5f15\uff0c\u89c4\u5212\u5668\u53ef\u80fd\u9009\u62e9\u7528 AND \u6216 OR \u7ec4\u5408\u8fd9\u4e9b\u7d22\u5f15\uff1a"]}, {"code": "EXPLAIN (ANALYZE, BUFFERS) SELECT * FROM tenk1 WHERE unique1 < 100 AND unique2 > 9000;\n\n QUERY PLAN\n---------------------------------------------------------------------------------------------------------------------------------\n Bitmap Heap Scan on tenk1 (cost=25.08..60.21 rows=10 width=244) (actual time=0.323..0.342 rows=10 loops=1)\n Recheck Cond: ((unique1 < 100) AND (unique2 > 9000))\n Buffers: shared hit=15\n -> BitmapAnd (cost=25.08..25.08 rows=10 width=0) (actual time=0.309..0.309 rows=0 loops=1)\n Buffers: shared hit=7\n -> Bitmap Index Scan on tenk1_unique1 (cost=0.00..5.04 rows=101 width=0) (actual time=0.043..0.043 rows=100 loops=1)\n Index Cond: (unique1 < 100)\n Buffers: shared hit=2\n -> Bitmap Index Scan on tenk1_unique2 (cost=0.00..19.78 rows=999 width=0) (actual time=0.227..0.227 rows=999 loops=1)\n Index Cond: (unique2 > 9000)\n Buffers: shared hit=5\n Planning time: 0.088 ms\n Execution time: 0.423 ms", "source": {"url": "/docs/16/using-explain.html#USING-EXPLAIN-ANALYZE", "path": "using-explain.html", "label": "PostgreSQL 16.15 \u00b7 using-explain", "sha256": "bd8b86e5281cf0e52ad6e0e4bb8b6ff6510dac61982b44f0c1dd07d54012db3c"}, "paragraphs": ["\u793a\u4f8b\u6458\u81ea PostgreSQL 16.15 \u624b\u518c\uff1b\u672c\u767e\u79d1\u672a\u5b9e\u9645\u6267\u884c\u6b64\u793a\u4f8b\u3002", "EXPLAIN \u7684 BUFFERS \u9009\u9879\u53ef\u4e0e ANALYZE \u914d\u5408\u4f7f\u7528\uff0c\u4ee5\u83b7\u53d6\u66f4\u591a\u8fd0\u884c\u65f6\u7edf\u8ba1\u4fe1\u606f\uff1a"]}]}, {"title": "\u6267\u884c\u5668\u5b9e\u73b0\u8bf4\u660e", "paragraphs": ["\u8bf4\u660e\uff1aBitmapAnd \u4e0d\u4f7f\u7528\u5de6\u53f3\u5b50\u6811\uff0c\u800c\u50cf Append \u4e00\u6837\u7ef4\u62a4\u5b50\u8ba1\u5212\u5217\u8868\u3002\u4e0d\u8fc7\u5176\u903b\u8f91\u6bd4 Append \u7b80\u5355\u5f97\u591a\uff0c\u56e0\u4e3a\u65e0\u9700\u5904\u7406\u6b63\u5411\u6216\u53cd\u5411\u6267\u884c\u3002", "\u5bf9\u6bcf\u4e2a\u5f85\u6267\u884c\u8ba1\u5212\u8c03\u7528 ExecInitNode\uff0c\u5e76\u5c06\u7ed3\u679c\u4fdd\u5b58\u5230 bitmapplanstates \u6570\u7ec4\u3002", "BitmapAnd \u8ba1\u5212\u6ca1\u6709\u8868\u8fbe\u5f0f\u4e0a\u4e0b\u6587\uff0c\u56e0\u4e3a\u5b83\u4eec\u4ece\u4e0d\u8c03\u7528 ExecQual \u6216 ExecProject\uff0c\u4e5f\u4e0d\u9700\u8981\u5143\u7ec4\u69fd\u3002", "\u5982\u679c\u5728\u4efb\u4f55\u9636\u6bb5\u5f97\u5230\u5b8c\u5168\u4e3a\u7a7a\u7684\u4f4d\u56fe\uff0c\u5c31\u53ef\u4ee5\u76f4\u63a5\u9000\u51fa\uff0c\u65e0\u9700\u6267\u884c\u5269\u4f59\u5b50\u8ba1\u5212\uff0c\u56e0\u4e3a\u518d\u8fdb\u884c AND \u8fd0\u7b97\u4e5f\u4e0d\u4f1a\u6539\u53d8\u7ed3\u679c\u3002\uff08\u6ce8\u610f\uff1aindxpath.c \u6309\u9009\u62e9\u7387\u5bf9\u5b50\u8ba1\u5212\u6392\u5e8f\uff0c\u5e94\u5f53\u80fd\u63d0\u9ad8\u51fa\u73b0\u8fd9\u79cd\u60c5\u51b5\u7684\u6982\u7387\u3002\uff09", "ExecReScan \u4e0d\u77e5\u9053\u5f53\u524d\u8282\u70b9\u7684\u5b50\u8ba1\u5212\uff0c\u56e0\u6b64\u5fc5\u987b\u81ea\u884c\u901a\u77e5\u5b50\u8ba1\u5212\u54ea\u4e9b\u53c2\u6570\u53d1\u751f\u4e86\u53d8\u5316\u3002"]}, {"code": "case T_BitmapAnd:\n\t\t\tpname = sname = \"BitmapAnd\";\n\t\t\tbreak;", "title": "\u6838\u5fc3\u6e90\u7801\u4e2d\u7684 EXPLAIN \u6807\u8bc6"}], "strategies": [], "description": ["\u5bf9\u5404\u5b50\u8ba1\u5212\u4ea7\u751f\u7684\u4f4d\u56fe\u6c42\u4ea4\u96c6\u3002"], "localization": {"status": "complete", "sources": [], "language": "zh", "original_text": {"/versions/16/description/0": "Intersects bitmaps produced by its child plans.", "/versions/16/facts/0/label": "Core node tag", "/versions/16/facts/1/label": "Structured EXPLAIN Node Type", "/versions/16/facts/2/label": "Inputs", "/versions/16/facts/2/value": "Bitmap-producing child plans", "/versions/16/facts/3/label": "Output", "/versions/16/facts/3/value": "Tuple-location bitmap, not a tuple stream", "/versions/16/facts/4/label": "Executor initializer", "/versions/16/facts/5/label": "Memory mechanism", "/versions/16/tables/0/title": "EXPLAIN labels in this source build", "/versions/16/related/1/label": "Using EXPLAIN", "/versions/16/related/2/label": "Parallel plans", "/versions/16/sections/0/title": "EXPLAIN names and attributes", "/versions/16/sections/1/title": "Memory and temporary storage", "/versions/16/sections/2/title": "Parallel execution and instrumentation", "/versions/16/sections/3/title": "Same-version manual discussion", "/versions/16/sections/4/title": "Examples from this manual build", "/versions/16/sections/5/title": "Executor implementation notes", "/versions/16/sections/6/title": "EXPLAIN identity in core source", "/versions/16/memory/description": "This extraction does not assign a universal memory limit or spill policy to this node. Inspect the same-build implementation and its expressions or provider.", "/versions/16/sections/0/paragraphs/0": "Structured formats use the Node Type above. Text-format spellings can also include operation, strategy, join type, scan direction or aggregation-stage attributes.", "/versions/16/sections/0/paragraphs/1": "Text names recorded by this source: BitmapAnd.", "/versions/16/sections/0/paragraphs/2": "Parallel-aware and parallel-safe are different plan properties. A node running inside a parallel worker is not necessarily a parallel-aware node.", "/versions/16/sections/1/paragraphs/0": "This extraction does not assign a universal memory limit or spill policy to this node. Inspect the same-build implementation and its expressions or provider.", "/versions/16/sections/2/paragraphs/0": "The source callbacks below can coordinate execution or collect worker instrumentation. Their presence is not a blanket claim that this node supports a shared parallel scan or shared state.", "/versions/16/sections/2/paragraphs/1": "Callbacks in this build: none extracted from this node implementation.", "/versions/16/sections/3/paragraphs/0": "BitmapAnd and BitmapOr nodes always report their actual row counts as zero, due to implementation limitations.", "/versions/16/sections/5/paragraphs/0": "NOTES BitmapAnd nodes don't make use of their left and right subtrees, rather they maintain a list of subplans, much like Append nodes. The logic is much simpler than Append, however, since we needn't cope with forward/backward execution.", "/versions/16/sections/5/paragraphs/1": "call ExecInitNode on each of the plans to be executed and save the results into the array \"bitmapplanstates\".", "/versions/16/sections/5/paragraphs/2": "BitmapAnd plans don't have expression contexts because they never call ExecQual or ExecProject. They don't need any tuple slots either.", "/versions/16/sections/5/paragraphs/3": "If at any stage we have a completely empty bitmap, we can fall out without evaluating the remaining subplans, since ANDing them can no longer change the result. (Note: the fact that indxpath.c orders the subplans by selectivity should make this case more likely to occur.)", "/versions/16/sections/5/paragraphs/4": "ExecReScan doesn't know about my subplans, so I have to do changed-parameter signaling myself.", "/versions/16/tables/0/columns/0/label": "Text-format label", "/versions/16/tables/0/columns/1/label": "Structured node identity", "/versions/16/sections/4/blocks/0/paragraphs/0": "Example copied from the PostgreSQL 16.15 manual; it was not executed for this collection.", "/versions/16/sections/4/blocks/0/paragraphs/1": "If there are separate indexes on several of the columns referenced in WHERE , the planner might choose to use an AND or OR combination of the indexes:", "/versions/16/sections/4/blocks/1/paragraphs/0": "Example copied from the PostgreSQL 16.15 manual; it was not executed for this collection.", "/versions/16/sections/4/blocks/1/paragraphs/1": "EXPLAIN has a BUFFERS option that can be used with ANALYZE to get even more run time statistics:"}, "fallback_fields": [], "source_language": "en", "original_snapshot_sha256": "d47b614fee09428156af928588b8a218baa4d9e1ec680b1aa4142277427432c5"}, "evidence_kind": "source and documentation", "explain_names": ["BitmapAnd"], "partial_modes": [], "comparison_data": {"node_tag": "T_BitmapAnd", "strategies": [], "text_names": ["BitmapAnd"], "initializer": "ExecInitBitmapAnd", "partial_modes": [], "memory_mechanism": "unclassified", "parallel_callbacks": []}, "comparison_hash": "ffac2f4c3c78a9e2f88eb2c2de755f5a69e40f1ac6d7e9bcb4ed08615c9cb803", "explain_prefixes": ["Parallel", "Async"], "runtime_verified": false, "source_inventory": {"explain": "src/backend/commands/explain.c", "executor": "src/backend/executor/execProcnode.c", "implementation": "src/backend/executor/nodeBitmapAnd.c"}, "parallel_callbacks": []}, "17": {"facts": [{"label": "\u6838\u5fc3\u8282\u70b9\u6807\u7b7e", "value": "T_BitmapAnd"}, {"label": "\u7ed3\u6784\u5316 EXPLAIN \u8282\u70b9\u7c7b\u578b", "value": "BitmapAnd"}, {"label": "\u8f93\u5165", "value": "\u4ea7\u751f\u4f4d\u56fe\u7684\u5b50\u8ba1\u5212"}, {"label": "\u8f93\u51fa", "value": "\u5143\u7ec4\u4f4d\u7f6e\u4f4d\u56fe\uff0c\u4e0d\u662f\u5143\u7ec4\u6d41"}, {"label": "\u6267\u884c\u5668\u521d\u59cb\u5316\u51fd\u6570", "value": "ExecInitBitmapAnd"}, {"label": "\u5185\u5b58\u673a\u5236", "value": "unclassified"}], "memory": {"evidence": [{"url": "https://ftp.postgresql.org/pub/source/v17.11/postgresql-17.11.tar.bz2", "path": "src/backend/executor/nodeBitmapAnd.c", "label": "src/backend/executor/nodeBitmapAnd.c", "sha256": "c86004ae4e1b0783ef28372663be71a9f3f7b020cafd835749d2041a5357c368", "archive_sha256": "dd27f2b3c59e73ed14aa3324901242bf69a032a6347805f274e6260322d42979"}], "mechanism": "unclassified", "description": 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"src/backend/executor/nodeBitmapAnd.c", "label": "src/backend/executor/nodeBitmapAnd.c", "sha256": "c86004ae4e1b0783ef28372663be71a9f3f7b020cafd835749d2041a5357c368", "archive_sha256": "dd27f2b3c59e73ed14aa3324901242bf69a032a6347805f274e6260322d42979"}, {"url": "https://ftp.postgresql.org/pub/source/v17.11/postgresql-17.11.tar.bz2", "path": "src/include/nodes/plannodes.h", "label": "src/include/nodes/plannodes.h", "sha256": "d390dd69e2d3f5085beb42b33e46ff0676a2959b916a12b82118a7e545f8e562", "archive_sha256": "dd27f2b3c59e73ed14aa3324901242bf69a032a6347805f274e6260322d42979"}, {"url": "https://pg.center/docs/17/using-explain.html#USING-EXPLAIN-CAVEATS", "path": "using-explain.html", "label": "PostgreSQL 17.11 \u00b7 using-explain", "sha256": "8e3422c77496cc53bfc225ccadda3e82eb23c8c362b8eb95e7fb02cdb315ea78", "language": "en", "original_url": "/docs/17/using-explain.html#USING-EXPLAIN-CAVEATS"}, {"url": "https://pg.center/docs/17/using-explain.html#USING-EXPLAIN-BASICS", "path": "using-explain.html", "label": "PostgreSQL 17.11 \u00b7 using-explain", "sha256": "8e3422c77496cc53bfc225ccadda3e82eb23c8c362b8eb95e7fb02cdb315ea78", "language": "en", "original_url": "/docs/17/using-explain.html#USING-EXPLAIN-BASICS"}, {"url": "https://pg.center/docs/17/using-explain.html#USING-EXPLAIN-ANALYZE", "path": "using-explain.html", "label": "PostgreSQL 17.11 \u00b7 using-explain", "sha256": "8e3422c77496cc53bfc225ccadda3e82eb23c8c362b8eb95e7fb02cdb315ea78", "language": "en", "original_url": "/docs/17/using-explain.html#USING-EXPLAIN-ANALYZE"}], "node_tag": "T_BitmapAnd", "sections": [{"title": "EXPLAIN \u540d\u79f0\u4e0e\u5c5e\u6027", "paragraphs": ["\u7ed3\u6784\u5316\u683c\u5f0f\u4f7f\u7528\u4e0a\u8ff0 Node Type\u3002\u6587\u672c\u683c\u5f0f\u540d\u79f0\u8fd8\u53ef\u80fd\u5305\u542b\u64cd\u4f5c\u3001\u7b56\u7565\u3001\u8fde\u63a5\u7c7b\u578b\u3001\u626b\u63cf\u65b9\u5411\u6216\u805a\u5408\u9636\u6bb5\u5c5e\u6027\u3002", "\u6b64\u6e90\u7801\u8bb0\u5f55\u7684\u6587\u672c\u540d\u79f0\uff1aBitmapAnd.", "\u5e76\u884c\u611f\u77e5\u4e0e\u5e76\u884c\u5b89\u5168\u662f\u4e0d\u540c\u7684\u8ba1\u5212\u5c5e\u6027\u3002\u5728\u5e76\u884c\u5de5\u4f5c\u8fdb\u7a0b\u5185\u8fd0\u884c\u7684\u8282\u70b9\u4e0d\u4e00\u5b9a\u662f\u5e76\u884c\u611f\u77e5\u8282\u70b9\u3002"]}, {"title": "\u5185\u5b58\u4e0e\u4e34\u65f6\u5b58\u50a8", "paragraphs": ["\u672c\u6b21\u62bd\u53d6\u4e0d\u4e3a\u6b64\u8282\u70b9\u8bbe\u5b9a\u7edf\u4e00\u7684\u5185\u5b58\u4e0a\u9650\u6216\u843d\u76d8\u7b56\u7565\u3002\u8bf7\u67e5\u770b\u540c\u4e00\u6784\u5efa\u7684\u5b9e\u73b0\u3001\u76f8\u5173\u8868\u8fbe\u5f0f\u6216\u63d0\u4f9b\u65b9\u3002"]}, {"title": "\u5e76\u884c\u6267\u884c\u4e0e\u8fd0\u884c\u4fe1\u606f\u91c7\u96c6", "paragraphs": ["\u4ee5\u4e0b\u6e90\u7801\u56de\u8c03\u53ef\u4ee5\u534f\u8c03\u6267\u884c\u6216\u6536\u96c6\u5de5\u4f5c\u8fdb\u7a0b\u7684\u6d4b\u91cf\u6570\u636e\u3002\u56de\u8c03\u5b58\u5728\u4e0d\u4ee3\u8868\u8be5\u8282\u70b9\u666e\u904d\u652f\u6301\u5171\u4eab\u5e76\u884c\u626b\u63cf\u6216\u5171\u4eab\u72b6\u6001\u3002", "\u6b64\u6784\u5efa\u7684\u56de\u8c03\uff1anone extracted from this node implementation."]}, {"title": "\u540c\u7248\u672c\u624b\u518c\u8bf4\u660e", "paragraphs": ["\u7531\u4e8e\u5b9e\u73b0\u4e0a\u7684\u9650\u5236\uff0cBitmapAnd \u548c BitmapOr \u8282\u70b9\u62a5\u544a\u7684\u5b9e\u9645\u884c\u6570\u59cb\u7ec8\u4e3a\u96f6\u3002"]}, {"title": "\u672c\u7248\u624b\u518c\u4e2d\u7684\u793a\u4f8b", "blocks": [{"code": "EXPLAIN SELECT * FROM tenk1 WHERE unique1 < 100 AND unique2 > 9000;\n\n QUERY PLAN\n-------------------------------------------------------------------------------------\n Bitmap Heap Scan on tenk1 (cost=25.07..60.11 rows=10 width=244)\n Recheck Cond: ((unique1 < 100) AND (unique2 > 9000))\n -> BitmapAnd (cost=25.07..25.07 rows=10 width=0)\n -> Bitmap Index Scan on tenk1_unique1 (cost=0.00..5.04 rows=100 width=0)\n Index Cond: (unique1 < 100)\n -> Bitmap Index Scan on tenk1_unique2 (cost=0.00..19.78 rows=999 width=0)\n Index Cond: (unique2 > 9000)", "source": {"url": "/docs/17/using-explain.html#USING-EXPLAIN-BASICS", "path": "using-explain.html", "label": "PostgreSQL 17.11 \u00b7 using-explain", "sha256": "8e3422c77496cc53bfc225ccadda3e82eb23c8c362b8eb95e7fb02cdb315ea78"}, "paragraphs": ["\u793a\u4f8b\u6458\u81ea PostgreSQL 17.11 \u624b\u518c\uff1b\u672c\u767e\u79d1\u672a\u5b9e\u9645\u6267\u884c\u6b64\u793a\u4f8b\u3002", "\u5982\u679c WHERE \u5f15\u7528\u7684\u591a\u4e2a\u5217\u4e0a\u5206\u522b\u5efa\u6709\u7d22\u5f15\uff0c\u89c4\u5212\u5668\u53ef\u80fd\u9009\u62e9\u7528 AND \u6216 OR \u7ec4\u5408\u8fd9\u4e9b\u7d22\u5f15\uff1a"]}, {"code": "EXPLAIN (ANALYZE, BUFFERS) SELECT * FROM tenk1 WHERE unique1 < 100 AND unique2 > 9000;\n\n QUERY PLAN\n---------------------------------------------------------------------------------------------------------------------------------\n Bitmap Heap Scan on tenk1 (cost=25.07..60.11 rows=10 width=244) (actual time=0.105..0.114 rows=10 loops=1)\n Recheck Cond: ((unique1 < 100) AND (unique2 > 9000))\n Heap Blocks: exact=10\n Buffers: shared hit=14 read=3\n -> BitmapAnd (cost=25.07..25.07 rows=10 width=0) (actual time=0.100..0.101 rows=0 loops=1)\n Buffers: shared hit=4 read=3\n -> Bitmap Index Scan on tenk1_unique1 (cost=0.00..5.04 rows=100 width=0) (actual time=0.027..0.027 rows=100 loops=1)\n Index Cond: (unique1 < 100)\n Buffers: shared hit=2\n -> Bitmap Index Scan on tenk1_unique2 (cost=0.00..19.78 rows=999 width=0) (actual time=0.070..0.070 rows=999 loops=1)\n Index Cond: (unique2 > 9000)\n Buffers: shared hit=2 read=3\n Planning:\n Buffers: shared hit=3\n Planning Time: 0.162 ms\n Execution Time: 0.143 ms", "source": {"url": "/docs/17/using-explain.html#USING-EXPLAIN-ANALYZE", "path": "using-explain.html", "label": "PostgreSQL 17.11 \u00b7 using-explain", "sha256": "8e3422c77496cc53bfc225ccadda3e82eb23c8c362b8eb95e7fb02cdb315ea78"}, "paragraphs": ["\u793a\u4f8b\u6458\u81ea PostgreSQL 17.11 \u624b\u518c\uff1b\u672c\u767e\u79d1\u672a\u5b9e\u9645\u6267\u884c\u6b64\u793a\u4f8b\u3002", "EXPLAIN \u7684 BUFFERS \u9009\u9879\u53ef\u4e0e ANALYZE \u914d\u5408\u4f7f\u7528\uff0c\u4ee5\u83b7\u53d6\u66f4\u591a\u8fd0\u884c\u65f6\u7edf\u8ba1\u4fe1\u606f\uff1a"]}]}, {"title": "\u6267\u884c\u5668\u5b9e\u73b0\u8bf4\u660e", "paragraphs": ["\u8bf4\u660e\uff1aBitmapAnd \u4e0d\u4f7f\u7528\u5de6\u53f3\u5b50\u6811\uff0c\u800c\u50cf Append \u4e00\u6837\u7ef4\u62a4\u5b50\u8ba1\u5212\u5217\u8868\u3002\u4e0d\u8fc7\u5176\u903b\u8f91\u6bd4 Append \u7b80\u5355\u5f97\u591a\uff0c\u56e0\u4e3a\u65e0\u9700\u5904\u7406\u6b63\u5411\u6216\u53cd\u5411\u6267\u884c\u3002", "\u5bf9\u6bcf\u4e2a\u5f85\u6267\u884c\u8ba1\u5212\u8c03\u7528 ExecInitNode\uff0c\u5e76\u5c06\u7ed3\u679c\u4fdd\u5b58\u5230 bitmapplanstates \u6570\u7ec4\u3002", "BitmapAnd \u8ba1\u5212\u6ca1\u6709\u8868\u8fbe\u5f0f\u4e0a\u4e0b\u6587\uff0c\u56e0\u4e3a\u5b83\u4eec\u4ece\u4e0d\u8c03\u7528 ExecQual \u6216 ExecProject\uff0c\u4e5f\u4e0d\u9700\u8981\u5143\u7ec4\u69fd\u3002", "\u5982\u679c\u5728\u4efb\u4f55\u9636\u6bb5\u5f97\u5230\u5b8c\u5168\u4e3a\u7a7a\u7684\u4f4d\u56fe\uff0c\u5c31\u53ef\u4ee5\u76f4\u63a5\u9000\u51fa\uff0c\u65e0\u9700\u6267\u884c\u5269\u4f59\u5b50\u8ba1\u5212\uff0c\u56e0\u4e3a\u518d\u8fdb\u884c AND \u8fd0\u7b97\u4e5f\u4e0d\u4f1a\u6539\u53d8\u7ed3\u679c\u3002\uff08\u6ce8\u610f\uff1aindxpath.c \u6309\u9009\u62e9\u7387\u5bf9\u5b50\u8ba1\u5212\u6392\u5e8f\uff0c\u5e94\u5f53\u80fd\u63d0\u9ad8\u51fa\u73b0\u8fd9\u79cd\u60c5\u51b5\u7684\u6982\u7387\u3002\uff09", "ExecReScan \u4e0d\u77e5\u9053\u5f53\u524d\u8282\u70b9\u7684\u5b50\u8ba1\u5212\uff0c\u56e0\u6b64\u5fc5\u987b\u81ea\u884c\u901a\u77e5\u5b50\u8ba1\u5212\u54ea\u4e9b\u53c2\u6570\u53d1\u751f\u4e86\u53d8\u5316\u3002"]}, {"code": "case T_BitmapAnd:\n\t\t\tpname = sname = \"BitmapAnd\";\n\t\t\tbreak;", "title": "\u6838\u5fc3\u6e90\u7801\u4e2d\u7684 EXPLAIN \u6807\u8bc6"}], "strategies": [], "description": ["\u5bf9\u5404\u5b50\u8ba1\u5212\u4ea7\u751f\u7684\u4f4d\u56fe\u6c42\u4ea4\u96c6\u3002"], "localization": {"status": "complete", "sources": [], "language": "zh", "original_text": {"/versions/17/description/0": "Intersects bitmaps produced by its child plans.", "/versions/17/facts/0/label": "Core node tag", "/versions/17/facts/1/label": "Structured EXPLAIN Node Type", "/versions/17/facts/2/label": "Inputs", "/versions/17/facts/2/value": "Bitmap-producing child plans", "/versions/17/facts/3/label": "Output", "/versions/17/facts/3/value": "Tuple-location bitmap, not a tuple stream", "/versions/17/facts/4/label": "Executor initializer", "/versions/17/facts/5/label": "Memory mechanism", "/versions/17/tables/0/title": "EXPLAIN labels in this source build", "/versions/17/related/1/label": "Using EXPLAIN", "/versions/17/related/2/label": "Parallel plans", "/versions/17/sections/0/title": "EXPLAIN names and attributes", "/versions/17/sections/1/title": "Memory and temporary storage", "/versions/17/sections/2/title": "Parallel execution and instrumentation", "/versions/17/sections/3/title": "Same-version manual discussion", "/versions/17/sections/4/title": "Examples from this manual build", "/versions/17/sections/5/title": "Executor implementation notes", "/versions/17/sections/6/title": "EXPLAIN identity in core source", "/versions/17/memory/description": "This extraction does not assign a universal memory limit or spill policy to this node. Inspect the same-build implementation and its expressions or provider.", "/versions/17/sections/0/paragraphs/0": "Structured formats use the Node Type above. Text-format spellings can also include operation, strategy, join type, scan direction or aggregation-stage attributes.", "/versions/17/sections/0/paragraphs/1": "Text names recorded by this source: BitmapAnd.", "/versions/17/sections/0/paragraphs/2": "Parallel-aware and parallel-safe are different plan properties. A node running inside a parallel worker is not necessarily a parallel-aware node.", "/versions/17/sections/1/paragraphs/0": "This extraction does not assign a universal memory limit or spill policy to this node. Inspect the same-build implementation and its expressions or provider.", "/versions/17/sections/2/paragraphs/0": "The source callbacks below can coordinate execution or collect worker instrumentation. Their presence is not a blanket claim that this node supports a shared parallel scan or shared state.", "/versions/17/sections/2/paragraphs/1": "Callbacks in this build: none extracted from this node implementation.", "/versions/17/sections/3/paragraphs/0": "BitmapAnd and BitmapOr nodes always report their actual row counts as zero, due to implementation limitations.", "/versions/17/sections/5/paragraphs/0": "NOTES BitmapAnd nodes don't make use of their left and right subtrees, rather they maintain a list of subplans, much like Append nodes. The logic is much simpler than Append, however, since we needn't cope with forward/backward execution.", "/versions/17/sections/5/paragraphs/1": "call ExecInitNode on each of the plans to be executed and save the results into the array \"bitmapplanstates\".", "/versions/17/sections/5/paragraphs/2": "BitmapAnd plans don't have expression contexts because they never call ExecQual or ExecProject. They don't need any tuple slots either.", "/versions/17/sections/5/paragraphs/3": "If at any stage we have a completely empty bitmap, we can fall out without evaluating the remaining subplans, since ANDing them can no longer change the result. (Note: the fact that indxpath.c orders the subplans by selectivity should make this case more likely to occur.)", "/versions/17/sections/5/paragraphs/4": "ExecReScan doesn't know about my subplans, so I have to do changed-parameter signaling myself.", "/versions/17/tables/0/columns/0/label": "Text-format label", "/versions/17/tables/0/columns/1/label": "Structured node identity", "/versions/17/sections/4/blocks/0/paragraphs/0": "Example copied from the PostgreSQL 17.11 manual; it was not executed for this collection.", "/versions/17/sections/4/blocks/0/paragraphs/1": "If there are separate indexes on several of the columns referenced in WHERE , the planner might choose to use an AND or OR combination of the indexes:", "/versions/17/sections/4/blocks/1/paragraphs/0": "Example copied from the PostgreSQL 17.11 manual; it was not executed for this collection.", "/versions/17/sections/4/blocks/1/paragraphs/1": "EXPLAIN has a BUFFERS option that can be used with ANALYZE to get even more run time statistics:"}, "fallback_fields": [], "source_language": "en", "original_snapshot_sha256": "112ab67582ce54c3f19e96d22c197bd2a19b7ed3a18441c42f43c90fd4827919"}, "evidence_kind": "source and documentation", "explain_names": ["BitmapAnd"], "partial_modes": [], "comparison_data": {"node_tag": "T_BitmapAnd", "strategies": [], "text_names": ["BitmapAnd"], "initializer": "ExecInitBitmapAnd", "partial_modes": [], "memory_mechanism": "unclassified", "parallel_callbacks": []}, "comparison_hash": "ffac2f4c3c78a9e2f88eb2c2de755f5a69e40f1ac6d7e9bcb4ed08615c9cb803", "explain_prefixes": ["Parallel", "Async"], "runtime_verified": false, "source_inventory": {"explain": "src/backend/commands/explain.c", "executor": "src/backend/executor/execProcnode.c", "implementation": "src/backend/executor/nodeBitmapAnd.c"}, "parallel_callbacks": []}, "18": {"facts": [{"label": "\u6838\u5fc3\u8282\u70b9\u6807\u7b7e", "value": "T_BitmapAnd"}, {"label": "\u7ed3\u6784\u5316 EXPLAIN \u8282\u70b9\u7c7b\u578b", "value": "BitmapAnd"}, {"label": "\u8f93\u5165", "value": "\u4ea7\u751f\u4f4d\u56fe\u7684\u5b50\u8ba1\u5212"}, {"label": "\u8f93\u51fa", "value": "\u5143\u7ec4\u4f4d\u7f6e\u4f4d\u56fe\uff0c\u4e0d\u662f\u5143\u7ec4\u6d41"}, {"label": "\u6267\u884c\u5668\u521d\u59cb\u5316\u51fd\u6570", "value": "ExecInitBitmapAnd"}, {"label": "\u5185\u5b58\u673a\u5236", "value": "unclassified"}], "memory": {"evidence": [{"url": "https://ftp.postgresql.org/pub/source/v18.6/postgresql-18.6.tar.bz2", "path": "src/backend/executor/nodeBitmapAnd.c", "label": "src/backend/executor/nodeBitmapAnd.c", "sha256": "ec359e3996322cd5f16aab61f23a38e26dae336bbcea4db735a6a70e0ecc89dd", "archive_sha256": "555610c24d53e4316da5b7d3fc25c279d96856d5e0e23ee308c328c5fa881d9f"}], "mechanism": "unclassified", "description": "\u672c\u6b21\u62bd\u53d6\u4e0d\u4e3a\u6b64\u8282\u70b9\u8bbe\u5b9a\u7edf\u4e00\u7684\u5185\u5b58\u4e0a\u9650\u6216\u843d\u76d8\u7b56\u7565\u3002\u8bf7\u67e5\u770b\u540c\u4e00\u6784\u5efa\u7684\u5b9e\u73b0\u3001\u76f8\u5173\u8868\u8fbe\u5f0f\u6216\u63d0\u4f9b\u65b9\u3002", "source_notes": []}, "tables": [{"key": "explain-labels", "rows": [{"label": "BitmapAnd", "identity": "BitmapAnd"}], "title": "\u672c\u6784\u5efa\u4e2d\u7684 EXPLAIN \u6807\u7b7e", "columns": [{"key": "label", "label": "\u6587\u672c\u683c\u5f0f\u6807\u7b7e"}, {"key": "identity", "label": "\u7ed3\u6784\u5316\u8282\u70b9\u6807\u8bc6"}]}], "related": [{"url": "/wiki/sql/explain/?v=18", "label": "EXPLAIN"}, {"url": "/docs/18/using-explain.html", "label": "\u4f7f\u7528 EXPLAIN"}, {"url": "/docs/18/parallel-plans.html", "label": "\u5e76\u884c\u8ba1\u5212"}], "release": {"ref": "PostgreSQL 18.6 source archive", "label": "18.6", "major": "18", "channel": "stable", "revision": "555610c24d53e4316da5b7d3fc25c279d96856d5e0e23ee308c328c5fa881d9f", "source_url": "https://ftp.postgresql.org/pub/source/v18.6/postgresql-18.6.tar.bz2", "source_snapshot_utc": ""}, "sources": [{"url": "https://ftp.postgresql.org/pub/source/v18.6/postgresql-18.6.tar.bz2", "line": 1415, "path": "src/backend/commands/explain.c", "label": "src/backend/commands/explain.c:1415", "sha256": "34c86d6070224a0e981efef51f79101d6d505e5874f1684ace183034bab14bb4", "archive_sha256": "555610c24d53e4316da5b7d3fc25c279d96856d5e0e23ee308c328c5fa881d9f"}, {"url": "https://ftp.postgresql.org/pub/source/v18.6/postgresql-18.6.tar.bz2", "line": 196, "path": "src/backend/executor/execProcnode.c", "label": "src/backend/executor/execProcnode.c:196", "sha256": "f8a06a3f539077249b20664b2812433db6d7bd12b2c0ca633525db43d06f112a", "archive_sha256": "555610c24d53e4316da5b7d3fc25c279d96856d5e0e23ee308c328c5fa881d9f"}, {"url": "https://ftp.postgresql.org/pub/source/v18.6/postgresql-18.6.tar.bz2", "path": "src/backend/executor/nodeBitmapAnd.c", "label": "src/backend/executor/nodeBitmapAnd.c", "sha256": "ec359e3996322cd5f16aab61f23a38e26dae336bbcea4db735a6a70e0ecc89dd", "archive_sha256": "555610c24d53e4316da5b7d3fc25c279d96856d5e0e23ee308c328c5fa881d9f"}, {"url": "https://ftp.postgresql.org/pub/source/v18.6/postgresql-18.6.tar.bz2", "path": "src/include/nodes/plannodes.h", "label": "src/include/nodes/plannodes.h", "sha256": "52422b327a8049fbbb20d8b96008a0fc0a6fafa60f7eff3c695d5b2e83830120", "archive_sha256": "555610c24d53e4316da5b7d3fc25c279d96856d5e0e23ee308c328c5fa881d9f"}, {"url": "https://pg.center/docs/18/using-explain.html#USING-EXPLAIN-CAVEATS", "path": "using-explain.html", "label": "PostgreSQL 18.6 \u00b7 using-explain", "sha256": "60040c30180093418a0affe56dd27dff9df2504b705b38039589e458bf5c31ed", "language": "en", "original_url": "/docs/18/using-explain.html#USING-EXPLAIN-CAVEATS"}, {"url": "https://pg.center/docs/18/using-explain.html#USING-EXPLAIN-BASICS", "path": "using-explain.html", "label": "PostgreSQL 18.6 \u00b7 using-explain", "sha256": "60040c30180093418a0affe56dd27dff9df2504b705b38039589e458bf5c31ed", "language": "en", "original_url": "/docs/18/using-explain.html#USING-EXPLAIN-BASICS"}, {"url": "https://pg.center/docs/18/using-explain.html#USING-EXPLAIN-ANALYZE", "path": "using-explain.html", "label": "PostgreSQL 18.6 \u00b7 using-explain", "sha256": "60040c30180093418a0affe56dd27dff9df2504b705b38039589e458bf5c31ed", "language": "en", "original_url": "/docs/18/using-explain.html#USING-EXPLAIN-ANALYZE"}], "node_tag": "T_BitmapAnd", "sections": [{"title": "EXPLAIN \u540d\u79f0\u4e0e\u5c5e\u6027", "paragraphs": ["\u7ed3\u6784\u5316\u683c\u5f0f\u4f7f\u7528\u4e0a\u8ff0 Node Type\u3002\u6587\u672c\u683c\u5f0f\u540d\u79f0\u8fd8\u53ef\u80fd\u5305\u542b\u64cd\u4f5c\u3001\u7b56\u7565\u3001\u8fde\u63a5\u7c7b\u578b\u3001\u626b\u63cf\u65b9\u5411\u6216\u805a\u5408\u9636\u6bb5\u5c5e\u6027\u3002", "\u6b64\u6e90\u7801\u8bb0\u5f55\u7684\u6587\u672c\u540d\u79f0\uff1aBitmapAnd.", "\u5e76\u884c\u611f\u77e5\u4e0e\u5e76\u884c\u5b89\u5168\u662f\u4e0d\u540c\u7684\u8ba1\u5212\u5c5e\u6027\u3002\u5728\u5e76\u884c\u5de5\u4f5c\u8fdb\u7a0b\u5185\u8fd0\u884c\u7684\u8282\u70b9\u4e0d\u4e00\u5b9a\u662f\u5e76\u884c\u611f\u77e5\u8282\u70b9\u3002"]}, {"title": "\u5185\u5b58\u4e0e\u4e34\u65f6\u5b58\u50a8", "paragraphs": ["\u672c\u6b21\u62bd\u53d6\u4e0d\u4e3a\u6b64\u8282\u70b9\u8bbe\u5b9a\u7edf\u4e00\u7684\u5185\u5b58\u4e0a\u9650\u6216\u843d\u76d8\u7b56\u7565\u3002\u8bf7\u67e5\u770b\u540c\u4e00\u6784\u5efa\u7684\u5b9e\u73b0\u3001\u76f8\u5173\u8868\u8fbe\u5f0f\u6216\u63d0\u4f9b\u65b9\u3002"]}, {"title": "\u5e76\u884c\u6267\u884c\u4e0e\u8fd0\u884c\u4fe1\u606f\u91c7\u96c6", "paragraphs": ["\u4ee5\u4e0b\u6e90\u7801\u56de\u8c03\u53ef\u4ee5\u534f\u8c03\u6267\u884c\u6216\u6536\u96c6\u5de5\u4f5c\u8fdb\u7a0b\u7684\u6d4b\u91cf\u6570\u636e\u3002\u56de\u8c03\u5b58\u5728\u4e0d\u4ee3\u8868\u8be5\u8282\u70b9\u666e\u904d\u652f\u6301\u5171\u4eab\u5e76\u884c\u626b\u63cf\u6216\u5171\u4eab\u72b6\u6001\u3002", "\u6b64\u6784\u5efa\u7684\u56de\u8c03\uff1anone extracted from this node implementation."]}, {"title": "\u540c\u7248\u672c\u624b\u518c\u8bf4\u660e", "paragraphs": ["\u7531\u4e8e\u5b9e\u73b0\u4e0a\u7684\u9650\u5236\uff0cBitmapAnd \u548c BitmapOr \u8282\u70b9\u62a5\u544a\u7684\u5b9e\u9645\u884c\u6570\u59cb\u7ec8\u4e3a\u96f6\u3002"]}, {"title": "\u672c\u7248\u624b\u518c\u4e2d\u7684\u793a\u4f8b", "blocks": [{"code": "EXPLAIN SELECT * FROM tenk1 WHERE unique1 < 100 AND unique2 > 9000;\n\n QUERY PLAN\n-------------------------------------------------------------------------------------\n Bitmap Heap Scan on tenk1 (cost=25.07..60.11 rows=10 width=244)\n Recheck Cond: ((unique1 < 100) AND (unique2 > 9000))\n -> BitmapAnd (cost=25.07..25.07 rows=10 width=0)\n -> Bitmap Index Scan on tenk1_unique1 (cost=0.00..5.04 rows=100 width=0)\n Index Cond: (unique1 < 100)\n -> Bitmap Index Scan on tenk1_unique2 (cost=0.00..19.78 rows=999 width=0)\n Index Cond: (unique2 > 9000)", "source": {"url": "/docs/18/using-explain.html#USING-EXPLAIN-BASICS", "path": "using-explain.html", "label": "PostgreSQL 18.6 \u00b7 using-explain", "sha256": "60040c30180093418a0affe56dd27dff9df2504b705b38039589e458bf5c31ed"}, "paragraphs": ["\u793a\u4f8b\u6458\u81ea PostgreSQL 18.6 \u624b\u518c\uff1b\u672c\u767e\u79d1\u672a\u5b9e\u9645\u6267\u884c\u6b64\u793a\u4f8b\u3002", "\u5982\u679c WHERE \u5f15\u7528\u7684\u591a\u4e2a\u5217\u4e0a\u5206\u522b\u5efa\u6709\u7d22\u5f15\uff0c\u89c4\u5212\u5668\u53ef\u80fd\u9009\u62e9\u7528 AND \u6216 OR \u7ec4\u5408\u8fd9\u4e9b\u7d22\u5f15\uff1a"]}, {"code": "EXPLAIN (ANALYZE, BUFFERS OFF) SELECT * FROM tenk1 WHERE unique1 < 100 AND unique2 > 9000;\n\n QUERY PLAN\n---------------------------------------------------------------------------------------------------------------------------------\n Bitmap Heap Scan on tenk1 (cost=25.07..60.11 rows=10 width=244) (actual time=0.105..0.114 rows=10.00 loops=1)\n Recheck Cond: ((unique1 < 100) AND (unique2 > 9000))\n Heap Blocks: exact=10\n -> BitmapAnd (cost=25.07..25.07 rows=10 width=0) (actual time=0.100..0.101 rows=0.00 loops=1)\n -> Bitmap Index Scan on tenk1_unique1 (cost=0.00..5.04 rows=100 width=0) (actual time=0.027..0.027 rows=100.00 loops=1)\n Index Cond: (unique1 < 100)\n Index Searches: 1\n -> Bitmap Index Scan on tenk1_unique2 (cost=0.00..19.78 rows=999 width=0) (actual time=0.070..0.070 rows=999.00 loops=1)\n Index Cond: (unique2 > 9000)\n Index Searches: 1\n Planning Time: 0.162 ms\n Execution Time: 0.143 ms", "source": {"url": "/docs/18/using-explain.html#USING-EXPLAIN-ANALYZE", "path": "using-explain.html", "label": "PostgreSQL 18.6 \u00b7 using-explain", "sha256": "60040c30180093418a0affe56dd27dff9df2504b705b38039589e458bf5c31ed"}, "paragraphs": ["\u793a\u4f8b\u6458\u81ea PostgreSQL 18.6 \u624b\u518c\uff1b\u672c\u767e\u79d1\u672a\u5b9e\u9645\u6267\u884c\u6b64\u793a\u4f8b\u3002", "EXPLAIN \u6709\u4e00\u4e2a BUFFERS \u9009\u9879\uff0c\u53ef\u4e3a\u7ed9\u5b9a\u67e5\u8be2\u5728\u89c4\u5212\u548c\u6267\u884c\u671f\u95f4\u6267\u884c\u7684 I/O \u64cd\u4f5c\u63d0\u4f9b\u66f4\u8be6\u7ec6\u7684\u4fe1\u606f\u3002\u663e\u793a\u51fa\u6765\u7684\u7f13\u51b2\u533a\u6570\u5b57\uff0c\u662f\u8be5\u8282\u70b9\u53ca\u5176\u6240\u6709\u5b50\u8282\u70b9\u6240\u547d\u4e2d\u7684\u3001\u8bfb\u53d6\u7684\u3001\u5f04\u810f\u7684\u548c\u5199\u51fa\u7684\u975e\u53bb\u91cd\u7f13\u51b2\u533a\u603b\u6570\u3002 ANALYZE \u9009\u9879\u4f1a\u9690\u5f0f\u542f\u7528 BUFFERS \u3002\u5982\u679c\u4e0d\u5e0c\u671b\u5982\u6b64\uff0c\u4e5f\u53ef\u4ee5\u663e\u5f0f\u5173\u95ed BUFFERS \uff1a"]}]}, {"title": "\u6267\u884c\u5668\u5b9e\u73b0\u8bf4\u660e", "paragraphs": ["\u8bf4\u660e\uff1aBitmapAnd \u4e0d\u4f7f\u7528\u5de6\u53f3\u5b50\u6811\uff0c\u800c\u50cf Append \u4e00\u6837\u7ef4\u62a4\u5b50\u8ba1\u5212\u5217\u8868\u3002\u4e0d\u8fc7\u5176\u903b\u8f91\u6bd4 Append \u7b80\u5355\u5f97\u591a\uff0c\u56e0\u4e3a\u65e0\u9700\u5904\u7406\u6b63\u5411\u6216\u53cd\u5411\u6267\u884c\u3002", "\u5bf9\u6bcf\u4e2a\u5f85\u6267\u884c\u8ba1\u5212\u8c03\u7528 ExecInitNode\uff0c\u5e76\u5c06\u7ed3\u679c\u4fdd\u5b58\u5230 bitmapplanstates \u6570\u7ec4\u3002", "BitmapAnd \u8ba1\u5212\u6ca1\u6709\u8868\u8fbe\u5f0f\u4e0a\u4e0b\u6587\uff0c\u56e0\u4e3a\u5b83\u4eec\u4ece\u4e0d\u8c03\u7528 ExecQual \u6216 ExecProject\uff0c\u4e5f\u4e0d\u9700\u8981\u5143\u7ec4\u69fd\u3002", "\u5982\u679c\u5728\u4efb\u4f55\u9636\u6bb5\u5f97\u5230\u5b8c\u5168\u4e3a\u7a7a\u7684\u4f4d\u56fe\uff0c\u5c31\u53ef\u4ee5\u76f4\u63a5\u9000\u51fa\uff0c\u65e0\u9700\u6267\u884c\u5269\u4f59\u5b50\u8ba1\u5212\uff0c\u56e0\u4e3a\u518d\u8fdb\u884c AND \u8fd0\u7b97\u4e5f\u4e0d\u4f1a\u6539\u53d8\u7ed3\u679c\u3002\uff08\u6ce8\u610f\uff1aindxpath.c \u6309\u9009\u62e9\u7387\u5bf9\u5b50\u8ba1\u5212\u6392\u5e8f\uff0c\u5e94\u5f53\u80fd\u63d0\u9ad8\u51fa\u73b0\u8fd9\u79cd\u60c5\u51b5\u7684\u6982\u7387\u3002\uff09", "ExecReScan \u4e0d\u77e5\u9053\u5f53\u524d\u8282\u70b9\u7684\u5b50\u8ba1\u5212\uff0c\u56e0\u6b64\u5fc5\u987b\u81ea\u884c\u901a\u77e5\u5b50\u8ba1\u5212\u54ea\u4e9b\u53c2\u6570\u53d1\u751f\u4e86\u53d8\u5316\u3002"]}, {"code": "case T_BitmapAnd:\n\t\t\tpname = sname = \"BitmapAnd\";\n\t\t\tbreak;", "title": "\u6838\u5fc3\u6e90\u7801\u4e2d\u7684 EXPLAIN \u6807\u8bc6"}], "strategies": [], "description": ["\u5bf9\u5404\u5b50\u8ba1\u5212\u4ea7\u751f\u7684\u4f4d\u56fe\u6c42\u4ea4\u96c6\u3002"], "localization": {"status": "complete", "sources": [{"url": "/docs/18/using-explain.html", "method": "same-major semantic node", "sha256": "b8835ec9adbc70ec150667a6b5443f8d298222dc0cc8c2bd1abb1c1d64895904", "language": "zh", "matched_nodes": ["#USING-EXPLAIN/div[8]/p[24]"]}], "language": "zh", "original_text": {"/versions/18/description/0": "Intersects bitmaps produced by its child plans.", "/versions/18/facts/0/label": "Core node tag", "/versions/18/facts/1/label": "Structured EXPLAIN Node Type", "/versions/18/facts/2/label": "Inputs", "/versions/18/facts/2/value": "Bitmap-producing child plans", "/versions/18/facts/3/label": "Output", "/versions/18/facts/3/value": "Tuple-location bitmap, not a tuple stream", "/versions/18/facts/4/label": "Executor initializer", "/versions/18/facts/5/label": "Memory mechanism", "/versions/18/tables/0/title": "EXPLAIN labels in this source build", "/versions/18/related/1/label": "Using EXPLAIN", "/versions/18/related/2/label": "Parallel plans", "/versions/18/sections/0/title": "EXPLAIN names and attributes", "/versions/18/sections/1/title": "Memory and temporary storage", "/versions/18/sections/2/title": "Parallel execution and instrumentation", "/versions/18/sections/3/title": "Same-version manual discussion", "/versions/18/sections/4/title": "Examples from this manual build", "/versions/18/sections/5/title": "Executor implementation notes", "/versions/18/sections/6/title": "EXPLAIN identity in core source", "/versions/18/memory/description": "This extraction does not assign a universal memory limit or spill policy to this node. Inspect the same-build implementation and its expressions or provider.", "/versions/18/sections/0/paragraphs/0": "Structured formats use the Node Type above. Text-format spellings can also include operation, strategy, join type, scan direction or aggregation-stage attributes.", "/versions/18/sections/0/paragraphs/1": "Text names recorded by this source: BitmapAnd.", "/versions/18/sections/0/paragraphs/2": "Parallel-aware and parallel-safe are different plan properties. A node running inside a parallel worker is not necessarily a parallel-aware node.", "/versions/18/sections/1/paragraphs/0": "This extraction does not assign a universal memory limit or spill policy to this node. Inspect the same-build implementation and its expressions or provider.", "/versions/18/sections/2/paragraphs/0": "The source callbacks below can coordinate execution or collect worker instrumentation. Their presence is not a blanket claim that this node supports a shared parallel scan or shared state.", "/versions/18/sections/2/paragraphs/1": "Callbacks in this build: none extracted from this node implementation.", "/versions/18/sections/3/paragraphs/0": "BitmapAnd and BitmapOr nodes always report their actual row counts as zero, due to implementation limitations.", "/versions/18/sections/5/paragraphs/0": "NOTES BitmapAnd nodes don't make use of their left and right subtrees, rather they maintain a list of subplans, much like Append nodes. The logic is much simpler than Append, however, since we needn't cope with forward/backward execution.", "/versions/18/sections/5/paragraphs/1": "call ExecInitNode on each of the plans to be executed and save the results into the array \"bitmapplanstates\".", "/versions/18/sections/5/paragraphs/2": "BitmapAnd plans don't have expression contexts because they never call ExecQual or ExecProject. They don't need any tuple slots either.", "/versions/18/sections/5/paragraphs/3": "If at any stage we have a completely empty bitmap, we can fall out without evaluating the remaining subplans, since ANDing them can no longer change the result. (Note: the fact that indxpath.c orders the subplans by selectivity should make this case more likely to occur.)", "/versions/18/sections/5/paragraphs/4": "ExecReScan doesn't know about my subplans, so I have to do changed-parameter signaling myself.", "/versions/18/tables/0/columns/0/label": "Text-format label", "/versions/18/tables/0/columns/1/label": "Structured node identity", "/versions/18/sections/4/blocks/0/paragraphs/0": "Example copied from the PostgreSQL 18.6 manual; it was not executed for this collection.", "/versions/18/sections/4/blocks/0/paragraphs/1": "If there are separate indexes on several of the columns referenced in WHERE , the planner might choose to use an AND or OR combination of the indexes:", "/versions/18/sections/4/blocks/1/paragraphs/0": "Example copied from the PostgreSQL 18.6 manual; it was not executed for this collection.", "/versions/18/sections/4/blocks/1/paragraphs/1": "EXPLAIN has a BUFFERS option which provides additional detail about I/O operations performed during the planning and execution of the given query. The buffer numbers displayed show the count of the non-distinct buffers hit, read, dirtied, and written for the given node and all of its child nodes. The ANALYZE option implicitly enables the BUFFERS option. If this is undesired, BUFFERS may be explicitly disabled:"}, "fallback_fields": [], "source_language": "en", "original_snapshot_sha256": "bba8a825b70e79bd2c74f204779852f7a3d89f07c47e58a4f951c9e386c477d1"}, "evidence_kind": "source and documentation", "explain_names": ["BitmapAnd"], "partial_modes": [], "comparison_data": {"node_tag": "T_BitmapAnd", "strategies": [], "text_names": ["BitmapAnd"], "initializer": "ExecInitBitmapAnd", "partial_modes": [], "memory_mechanism": "unclassified", "parallel_callbacks": []}, "comparison_hash": "ffac2f4c3c78a9e2f88eb2c2de755f5a69e40f1ac6d7e9bcb4ed08615c9cb803", "explain_prefixes": ["Parallel", "Async"], "runtime_verified": false, "source_inventory": {"explain": "src/backend/commands/explain.c", "executor": "src/backend/executor/execProcnode.c", "implementation": "src/backend/executor/nodeBitmapAnd.c"}, "parallel_callbacks": []}, "19": {"facts": [{"label": "\u6838\u5fc3\u8282\u70b9\u6807\u7b7e", "value": "T_BitmapAnd"}, {"label": "\u7ed3\u6784\u5316 EXPLAIN \u8282\u70b9\u7c7b\u578b", "value": "BitmapAnd"}, {"label": "\u8f93\u5165", "value": "\u4ea7\u751f\u4f4d\u56fe\u7684\u5b50\u8ba1\u5212"}, {"label": "\u8f93\u51fa", "value": "\u5143\u7ec4\u4f4d\u7f6e\u4f4d\u56fe\uff0c\u4e0d\u662f\u5143\u7ec4\u6d41"}, {"label": "\u6267\u884c\u5668\u521d\u59cb\u5316\u51fd\u6570", "value": "ExecInitBitmapAnd"}, {"label": "\u5185\u5b58\u673a\u5236", "value": "unclassified"}], "memory": {"evidence": [{"url": "https://ftp.postgresql.org/pub/source/v19beta4/postgresql-19beta4.tar.bz2", "path": "src/backend/executor/nodeBitmapAnd.c", "label": "src/backend/executor/nodeBitmapAnd.c", "sha256": "18f8afaa80ee549a64a6e7d1f55d795070c1e3a7971418cfd4c3ee77fd21464d", "archive_sha256": "83157ee9c599d03b2f7a3d73ef3a56ec24e0e79cc2b3501a64d1364f56398c86"}], "mechanism": "unclassified", "description": "\u672c\u6b21\u62bd\u53d6\u4e0d\u4e3a\u6b64\u8282\u70b9\u8bbe\u5b9a\u7edf\u4e00\u7684\u5185\u5b58\u4e0a\u9650\u6216\u843d\u76d8\u7b56\u7565\u3002\u8bf7\u67e5\u770b\u540c\u4e00\u6784\u5efa\u7684\u5b9e\u73b0\u3001\u76f8\u5173\u8868\u8fbe\u5f0f\u6216\u63d0\u4f9b\u65b9\u3002", "source_notes": []}, "tables": [{"key": "explain-labels", "rows": [{"label": "BitmapAnd", "identity": "BitmapAnd"}], "title": "\u672c\u6784\u5efa\u4e2d\u7684 EXPLAIN \u6807\u7b7e", "columns": [{"key": "label", "label": "\u6587\u672c\u683c\u5f0f\u6807\u7b7e"}, {"key": "identity", "label": "\u7ed3\u6784\u5316\u8282\u70b9\u6807\u8bc6"}]}], "related": [{"url": "/wiki/sql/explain/?v=19", "label": "EXPLAIN"}, {"url": "/docs/19/using-explain.html", "label": "\u4f7f\u7528 EXPLAIN"}, {"url": "/docs/19/parallel-plans.html", "label": "\u5e76\u884c\u8ba1\u5212"}], "release": {"ref": "PostgreSQL 19beta4 source archive", "label": "19beta4", "major": "19", "channel": "preview", "revision": "83157ee9c599d03b2f7a3d73ef3a56ec24e0e79cc2b3501a64d1364f56398c86", "source_url": "https://ftp.postgresql.org/pub/source/v19beta4/postgresql-19beta4.tar.bz2", "source_snapshot_utc": ""}, "sources": [{"url": "https://ftp.postgresql.org/pub/source/v19beta4/postgresql-19beta4.tar.bz2", "line": 1427, "path": "src/backend/commands/explain.c", "label": "src/backend/commands/explain.c:1427", "sha256": "8b115b1c194a4b54ae630209a741e293b1df49a9052f10b2de9ca092a48998e3", "archive_sha256": "83157ee9c599d03b2f7a3d73ef3a56ec24e0e79cc2b3501a64d1364f56398c86"}, {"url": "https://ftp.postgresql.org/pub/source/v19beta4/postgresql-19beta4.tar.bz2", "line": 196, "path": "src/backend/executor/execProcnode.c", "label": "src/backend/executor/execProcnode.c:196", "sha256": "5e39b2037bed672da55104229ecc32da5abde44c26bcad01479edcfa044d09ed", "archive_sha256": "83157ee9c599d03b2f7a3d73ef3a56ec24e0e79cc2b3501a64d1364f56398c86"}, {"url": "https://ftp.postgresql.org/pub/source/v19beta4/postgresql-19beta4.tar.bz2", "path": "src/backend/executor/nodeBitmapAnd.c", "label": "src/backend/executor/nodeBitmapAnd.c", "sha256": "18f8afaa80ee549a64a6e7d1f55d795070c1e3a7971418cfd4c3ee77fd21464d", "archive_sha256": "83157ee9c599d03b2f7a3d73ef3a56ec24e0e79cc2b3501a64d1364f56398c86"}, {"url": "https://ftp.postgresql.org/pub/source/v19beta4/postgresql-19beta4.tar.bz2", "path": "src/include/nodes/plannodes.h", "label": "src/include/nodes/plannodes.h", "sha256": "1c65d5d6b6c81c71531685843647869bcae630779d815a5036b06e070c6c06c7", "archive_sha256": "83157ee9c599d03b2f7a3d73ef3a56ec24e0e79cc2b3501a64d1364f56398c86"}, {"url": "https://pg.center/docs/19/using-explain.html#USING-EXPLAIN-CAVEATS", "path": "using-explain.html", "label": "PostgreSQL 19beta4 \u00b7 using-explain", "sha256": "52f111fbd213e2200146319d01a9dcc2ea90001617d2a28edc52f7954c2dd70b", "language": "en", "original_url": "/docs/19/using-explain.html#USING-EXPLAIN-CAVEATS"}, {"url": "https://pg.center/docs/19/using-explain.html#USING-EXPLAIN-BASICS", "path": "using-explain.html", "label": "PostgreSQL 19beta4 \u00b7 using-explain", "sha256": "52f111fbd213e2200146319d01a9dcc2ea90001617d2a28edc52f7954c2dd70b", "language": "en", "original_url": "/docs/19/using-explain.html#USING-EXPLAIN-BASICS"}, {"url": "https://pg.center/docs/19/using-explain.html#USING-EXPLAIN-ANALYZE", "path": "using-explain.html", "label": "PostgreSQL 19beta4 \u00b7 using-explain", "sha256": "52f111fbd213e2200146319d01a9dcc2ea90001617d2a28edc52f7954c2dd70b", "language": "en", "original_url": "/docs/19/using-explain.html#USING-EXPLAIN-ANALYZE"}], "node_tag": "T_BitmapAnd", "sections": [{"title": "EXPLAIN \u540d\u79f0\u4e0e\u5c5e\u6027", "paragraphs": ["\u7ed3\u6784\u5316\u683c\u5f0f\u4f7f\u7528\u4e0a\u8ff0 Node Type\u3002\u6587\u672c\u683c\u5f0f\u540d\u79f0\u8fd8\u53ef\u80fd\u5305\u542b\u64cd\u4f5c\u3001\u7b56\u7565\u3001\u8fde\u63a5\u7c7b\u578b\u3001\u626b\u63cf\u65b9\u5411\u6216\u805a\u5408\u9636\u6bb5\u5c5e\u6027\u3002", "\u6b64\u6e90\u7801\u8bb0\u5f55\u7684\u6587\u672c\u540d\u79f0\uff1aBitmapAnd.", "\u5e76\u884c\u611f\u77e5\u4e0e\u5e76\u884c\u5b89\u5168\u662f\u4e0d\u540c\u7684\u8ba1\u5212\u5c5e\u6027\u3002\u5728\u5e76\u884c\u5de5\u4f5c\u8fdb\u7a0b\u5185\u8fd0\u884c\u7684\u8282\u70b9\u4e0d\u4e00\u5b9a\u662f\u5e76\u884c\u611f\u77e5\u8282\u70b9\u3002"]}, {"title": "\u5185\u5b58\u4e0e\u4e34\u65f6\u5b58\u50a8", "paragraphs": ["\u672c\u6b21\u62bd\u53d6\u4e0d\u4e3a\u6b64\u8282\u70b9\u8bbe\u5b9a\u7edf\u4e00\u7684\u5185\u5b58\u4e0a\u9650\u6216\u843d\u76d8\u7b56\u7565\u3002\u8bf7\u67e5\u770b\u540c\u4e00\u6784\u5efa\u7684\u5b9e\u73b0\u3001\u76f8\u5173\u8868\u8fbe\u5f0f\u6216\u63d0\u4f9b\u65b9\u3002"]}, {"title": "\u5e76\u884c\u6267\u884c\u4e0e\u8fd0\u884c\u4fe1\u606f\u91c7\u96c6", "paragraphs": ["\u4ee5\u4e0b\u6e90\u7801\u56de\u8c03\u53ef\u4ee5\u534f\u8c03\u6267\u884c\u6216\u6536\u96c6\u5de5\u4f5c\u8fdb\u7a0b\u7684\u6d4b\u91cf\u6570\u636e\u3002\u56de\u8c03\u5b58\u5728\u4e0d\u4ee3\u8868\u8be5\u8282\u70b9\u666e\u904d\u652f\u6301\u5171\u4eab\u5e76\u884c\u626b\u63cf\u6216\u5171\u4eab\u72b6\u6001\u3002", "\u6b64\u6784\u5efa\u7684\u56de\u8c03\uff1anone extracted from this node implementation."]}, {"title": "\u540c\u7248\u672c\u624b\u518c\u8bf4\u660e", "paragraphs": ["\u7531\u4e8e\u5b9e\u73b0\u4e0a\u7684\u9650\u5236\uff0cBitmapAnd \u548c BitmapOr \u8282\u70b9\u62a5\u544a\u7684\u5b9e\u9645\u884c\u6570\u59cb\u7ec8\u4e3a\u96f6\u3002"]}, {"title": "\u672c\u7248\u624b\u518c\u4e2d\u7684\u793a\u4f8b", "blocks": [{"code": "EXPLAIN SELECT * FROM tenk1 WHERE unique1 < 100 AND unique2 > 9000;\n\n QUERY PLAN\n-------------------------------------------------------------------------------------\n Bitmap Heap Scan on tenk1 (cost=25.07..60.11 rows=10 width=244)\n Recheck Cond: ((unique1 < 100) AND (unique2 > 9000))\n -> BitmapAnd (cost=25.07..25.07 rows=10 width=0)\n -> Bitmap Index Scan on tenk1_unique1 (cost=0.00..5.04 rows=100 width=0)\n Index Cond: (unique1 < 100)\n -> Bitmap Index Scan on tenk1_unique2 (cost=0.00..19.78 rows=999 width=0)\n Index Cond: (unique2 > 9000)", "source": {"url": "/docs/19/using-explain.html#USING-EXPLAIN-BASICS", "path": "using-explain.html", "label": "PostgreSQL 19beta4 \u00b7 using-explain", "sha256": "52f111fbd213e2200146319d01a9dcc2ea90001617d2a28edc52f7954c2dd70b"}, "paragraphs": ["\u793a\u4f8b\u6458\u81ea PostgreSQL 19beta4 \u624b\u518c\uff1b\u672c\u767e\u79d1\u672a\u5b9e\u9645\u6267\u884c\u6b64\u793a\u4f8b\u3002", "\u5982\u679c WHERE \u5f15\u7528\u7684\u591a\u4e2a\u5217\u4e0a\u5206\u522b\u5efa\u6709\u7d22\u5f15\uff0c\u89c4\u5212\u5668\u53ef\u80fd\u9009\u62e9\u7528 AND \u6216 OR \u7ec4\u5408\u8fd9\u4e9b\u7d22\u5f15\uff1a"]}, {"code": "EXPLAIN (ANALYZE, BUFFERS OFF) SELECT * FROM tenk1 WHERE unique1 < 100 AND unique2 > 9000;\n\n QUERY PLAN\n---------------------------------------------------------------------------------------------------------------------------------\n Bitmap Heap Scan on tenk1 (cost=25.07..60.11 rows=10 width=244) (actual time=0.105..0.114 rows=10.00 loops=1)\n Recheck Cond: ((unique1 < 100) AND (unique2 > 9000))\n Heap Blocks: exact=10\n -> BitmapAnd (cost=25.07..25.07 rows=10 width=0) (actual time=0.100..0.101 rows=0.00 loops=1)\n -> Bitmap Index Scan on tenk1_unique1 (cost=0.00..5.04 rows=100 width=0) (actual time=0.027..0.027 rows=100.00 loops=1)\n Index Cond: (unique1 < 100)\n Index Searches: 1\n -> Bitmap Index Scan on tenk1_unique2 (cost=0.00..19.78 rows=999 width=0) (actual time=0.070..0.070 rows=999.00 loops=1)\n Index Cond: (unique2 > 9000)\n Index Searches: 1\n Planning Time: 0.162 ms\n Execution Time: 0.143 ms", "source": {"url": "/docs/19/using-explain.html#USING-EXPLAIN-ANALYZE", "path": "using-explain.html", "label": "PostgreSQL 19beta4 \u00b7 using-explain", "sha256": "52f111fbd213e2200146319d01a9dcc2ea90001617d2a28edc52f7954c2dd70b"}, "paragraphs": ["\u793a\u4f8b\u6458\u81ea PostgreSQL 19beta4 \u624b\u518c\uff1b\u672c\u767e\u79d1\u672a\u5b9e\u9645\u6267\u884c\u6b64\u793a\u4f8b\u3002", "EXPLAIN \u6709\u4e00\u4e2a BUFFERS \u9009\u9879\uff0c\u53ef\u4e3a\u7ed9\u5b9a\u67e5\u8be2\u5728\u89c4\u5212\u548c\u6267\u884c\u671f\u95f4\u6267\u884c\u7684 I/O \u64cd\u4f5c\u63d0\u4f9b\u66f4\u8be6\u7ec6\u7684\u4fe1\u606f\u3002\u663e\u793a\u51fa\u6765\u7684\u7f13\u51b2\u533a\u6570\u5b57\uff0c\u662f\u8be5\u8282\u70b9\u53ca\u5176\u6240\u6709\u5b50\u8282\u70b9\u6240\u547d\u4e2d\u7684\u3001\u8bfb\u53d6\u7684\u3001\u5f04\u810f\u7684\u548c\u5199\u51fa\u7684\u975e\u53bb\u91cd\u7f13\u51b2\u533a\u603b\u6570\u3002 ANALYZE \u9009\u9879\u4f1a\u9690\u5f0f\u542f\u7528 BUFFERS \u3002\u5982\u679c\u4e0d\u5e0c\u671b\u5982\u6b64\uff0c\u4e5f\u53ef\u4ee5\u663e\u5f0f\u5173\u95ed BUFFERS \uff1a"]}]}, {"title": "\u6267\u884c\u5668\u5b9e\u73b0\u8bf4\u660e", "paragraphs": ["\u8bf4\u660e\uff1aBitmapAnd \u4e0d\u4f7f\u7528\u5de6\u53f3\u5b50\u6811\uff0c\u800c\u50cf Append \u4e00\u6837\u7ef4\u62a4\u5b50\u8ba1\u5212\u5217\u8868\u3002\u4e0d\u8fc7\u5176\u903b\u8f91\u6bd4 Append \u7b80\u5355\u5f97\u591a\uff0c\u56e0\u4e3a\u65e0\u9700\u5904\u7406\u6b63\u5411\u6216\u53cd\u5411\u6267\u884c\u3002", "\u5bf9\u6bcf\u4e2a\u5f85\u6267\u884c\u8ba1\u5212\u8c03\u7528 ExecInitNode\uff0c\u5e76\u5c06\u7ed3\u679c\u4fdd\u5b58\u5230 bitmapplanstates \u6570\u7ec4\u3002", "BitmapAnd \u8ba1\u5212\u6ca1\u6709\u8868\u8fbe\u5f0f\u4e0a\u4e0b\u6587\uff0c\u56e0\u4e3a\u5b83\u4eec\u4ece\u4e0d\u8c03\u7528 ExecQual \u6216 ExecProject\uff0c\u4e5f\u4e0d\u9700\u8981\u5143\u7ec4\u69fd\u3002", "\u5982\u679c\u5728\u4efb\u4f55\u9636\u6bb5\u5f97\u5230\u5b8c\u5168\u4e3a\u7a7a\u7684\u4f4d\u56fe\uff0c\u5c31\u53ef\u4ee5\u76f4\u63a5\u9000\u51fa\uff0c\u65e0\u9700\u6267\u884c\u5269\u4f59\u5b50\u8ba1\u5212\uff0c\u56e0\u4e3a\u518d\u8fdb\u884c AND \u8fd0\u7b97\u4e5f\u4e0d\u4f1a\u6539\u53d8\u7ed3\u679c\u3002\uff08\u6ce8\u610f\uff1aindxpath.c \u6309\u9009\u62e9\u7387\u5bf9\u5b50\u8ba1\u5212\u6392\u5e8f\uff0c\u5e94\u5f53\u80fd\u63d0\u9ad8\u51fa\u73b0\u8fd9\u79cd\u60c5\u51b5\u7684\u6982\u7387\u3002\uff09", "ExecReScan \u4e0d\u77e5\u9053\u5f53\u524d\u8282\u70b9\u7684\u5b50\u8ba1\u5212\uff0c\u56e0\u6b64\u5fc5\u987b\u81ea\u884c\u901a\u77e5\u5b50\u8ba1\u5212\u54ea\u4e9b\u53c2\u6570\u53d1\u751f\u4e86\u53d8\u5316\u3002"]}, {"code": "case T_BitmapAnd:\n\t\t\tpname = sname = \"BitmapAnd\";\n\t\t\tbreak;", "title": "\u6838\u5fc3\u6e90\u7801\u4e2d\u7684 EXPLAIN \u6807\u8bc6"}], "strategies": [], "description": ["\u5bf9\u5404\u5b50\u8ba1\u5212\u4ea7\u751f\u7684\u4f4d\u56fe\u6c42\u4ea4\u96c6\u3002"], "localization": {"status": "complete", "sources": [{"url": "/docs/19/using-explain.html", "method": "same-major semantic node", "sha256": "7cc78f59bf29afb1811ece53e9d5c572a3f634d66d7422fb8761f19bc6811492", "language": "zh", "matched_nodes": ["#USING-EXPLAIN/div[8]/p[27]"]}], "language": "zh", "original_text": {"/versions/19/description/0": "Intersects bitmaps produced by its child plans.", "/versions/19/facts/0/label": "Core node tag", "/versions/19/facts/1/label": "Structured EXPLAIN Node Type", "/versions/19/facts/2/label": "Inputs", "/versions/19/facts/2/value": "Bitmap-producing child plans", "/versions/19/facts/3/label": "Output", "/versions/19/facts/3/value": "Tuple-location bitmap, not a tuple stream", "/versions/19/facts/4/label": "Executor initializer", "/versions/19/facts/5/label": "Memory mechanism", "/versions/19/tables/0/title": "EXPLAIN labels in this source build", "/versions/19/related/1/label": "Using EXPLAIN", "/versions/19/related/2/label": "Parallel plans", "/versions/19/sections/0/title": "EXPLAIN names and attributes", "/versions/19/sections/1/title": "Memory and temporary storage", "/versions/19/sections/2/title": "Parallel execution and instrumentation", "/versions/19/sections/3/title": "Same-version manual discussion", "/versions/19/sections/4/title": "Examples from this manual build", "/versions/19/sections/5/title": "Executor implementation notes", "/versions/19/sections/6/title": "EXPLAIN identity in core source", "/versions/19/memory/description": "This extraction does not assign a universal memory limit or spill policy to this node. Inspect the same-build implementation and its expressions or provider.", "/versions/19/sections/0/paragraphs/0": "Structured formats use the Node Type above. Text-format spellings can also include operation, strategy, join type, scan direction or aggregation-stage attributes.", "/versions/19/sections/0/paragraphs/1": "Text names recorded by this source: BitmapAnd.", "/versions/19/sections/0/paragraphs/2": "Parallel-aware and parallel-safe are different plan properties. A node running inside a parallel worker is not necessarily a parallel-aware node.", "/versions/19/sections/1/paragraphs/0": "This extraction does not assign a universal memory limit or spill policy to this node. Inspect the same-build implementation and its expressions or provider.", "/versions/19/sections/2/paragraphs/0": "The source callbacks below can coordinate execution or collect worker instrumentation. Their presence is not a blanket claim that this node supports a shared parallel scan or shared state.", "/versions/19/sections/2/paragraphs/1": "Callbacks in this build: none extracted from this node implementation.", "/versions/19/sections/3/paragraphs/0": "BitmapAnd and BitmapOr nodes always report their actual row counts as zero, due to implementation limitations.", "/versions/19/sections/5/paragraphs/0": "NOTES BitmapAnd nodes don't make use of their left and right subtrees, rather they maintain a list of subplans, much like Append nodes. The logic is much simpler than Append, however, since we needn't cope with forward/backward execution.", "/versions/19/sections/5/paragraphs/1": "call ExecInitNode on each of the plans to be executed and save the results into the array \"bitmapplanstates\".", "/versions/19/sections/5/paragraphs/2": "BitmapAnd plans don't have expression contexts because they never call ExecQual or ExecProject. They don't need any tuple slots either.", "/versions/19/sections/5/paragraphs/3": "If at any stage we have a completely empty bitmap, we can fall out without evaluating the remaining subplans, since ANDing them can no longer change the result. (Note: the fact that indxpath.c orders the subplans by selectivity should make this case more likely to occur.)", "/versions/19/sections/5/paragraphs/4": "ExecReScan doesn't know about my subplans, so I have to do changed-parameter signaling myself.", "/versions/19/tables/0/columns/0/label": "Text-format label", "/versions/19/tables/0/columns/1/label": "Structured node identity", "/versions/19/sections/4/blocks/0/paragraphs/0": "Example copied from the PostgreSQL 19beta4 manual; it was not executed for this collection.", "/versions/19/sections/4/blocks/0/paragraphs/1": "If there are separate indexes on several of the columns referenced in WHERE , the planner might choose to use an AND or OR combination of the indexes:", "/versions/19/sections/4/blocks/1/paragraphs/0": "Example copied from the PostgreSQL 19beta4 manual; it was not executed for this collection.", "/versions/19/sections/4/blocks/1/paragraphs/1": "EXPLAIN has a BUFFERS option which provides additional detail about I/O operations performed during the planning and execution of the given query. The buffer numbers displayed show the count of the non-distinct buffers hit, read, dirtied, and written for the given node and all of its child nodes. The ANALYZE option implicitly enables the BUFFERS option. If this is undesired, BUFFERS may be explicitly disabled:"}, "fallback_fields": [], "source_language": "en", "original_snapshot_sha256": "719e588c15424f8c9bdb6dc0fd6bad2fd49c65e83734fc161d171ce261f2ec96"}, "evidence_kind": "source and documentation", "explain_names": ["BitmapAnd"], "partial_modes": [], "comparison_data": {"node_tag": "T_BitmapAnd", "strategies": [], "text_names": ["BitmapAnd"], "initializer": "ExecInitBitmapAnd", "partial_modes": [], "memory_mechanism": "unclassified", "parallel_callbacks": []}, "comparison_hash": "ffac2f4c3c78a9e2f88eb2c2de755f5a69e40f1ac6d7e9bcb4ed08615c9cb803", "explain_prefixes": ["Parallel", "Async"], "runtime_verified": false, "source_inventory": {"explain": "src/backend/commands/explain.c", "executor": "src/backend/executor/execProcnode.c", "implementation": "src/backend/executor/nodeBitmapAnd.c"}, "parallel_callbacks": []}, "20": {"facts": [{"label": "\u6838\u5fc3\u8282\u70b9\u6807\u7b7e", "value": "T_BitmapAnd"}, {"label": "\u7ed3\u6784\u5316 EXPLAIN \u8282\u70b9\u7c7b\u578b", "value": "BitmapAnd"}, {"label": "\u8f93\u5165", "value": "\u4ea7\u751f\u4f4d\u56fe\u7684\u5b50\u8ba1\u5212"}, {"label": "\u8f93\u51fa", "value": "\u5143\u7ec4\u4f4d\u7f6e\u4f4d\u56fe\uff0c\u4e0d\u662f\u5143\u7ec4\u6d41"}, {"label": "\u6267\u884c\u5668\u521d\u59cb\u5316\u51fd\u6570", "value": "ExecInitBitmapAnd"}, {"label": "\u5185\u5b58\u673a\u5236", "value": "unclassified"}], "memory": {"evidence": [{"url": "https://ftp.postgresql.org/pub/snapshot/dev/postgresql-snapshot.tar.bz2", "path": "src/backend/executor/nodeBitmapAnd.c", "label": "src/backend/executor/nodeBitmapAnd.c", "sha256": "abe3988513ba535961cc5becec9234c985cd22cfb5836bba56053854b974304d", "archive_sha256": "4d3346909b201ac1648232cf290462a7070c119326f56196f1f0253ed80fae41"}], "mechanism": "unclassified", "description": "\u672c\u6b21\u62bd\u53d6\u4e0d\u4e3a\u6b64\u8282\u70b9\u8bbe\u5b9a\u7edf\u4e00\u7684\u5185\u5b58\u4e0a\u9650\u6216\u843d\u76d8\u7b56\u7565\u3002\u8bf7\u67e5\u770b\u540c\u4e00\u6784\u5efa\u7684\u5b9e\u73b0\u3001\u76f8\u5173\u8868\u8fbe\u5f0f\u6216\u63d0\u4f9b\u65b9\u3002", "source_notes": []}, "tables": [{"key": "explain-labels", "rows": [{"label": "BitmapAnd", "identity": "BitmapAnd"}], "title": "\u672c\u6784\u5efa\u4e2d\u7684 EXPLAIN \u6807\u7b7e", "columns": [{"key": "label", "label": "\u6587\u672c\u683c\u5f0f\u6807\u7b7e"}, {"key": "identity", "label": "\u7ed3\u6784\u5316\u8282\u70b9\u6807\u8bc6"}]}], "related": [{"url": "/wiki/sql/explain/?v=20", "label": "EXPLAIN"}, {"url": "/docs/devel/using-explain.html", "label": "\u4f7f\u7528 EXPLAIN"}, {"url": "/docs/devel/parallel-plans.html", "label": "\u5e76\u884c\u8ba1\u5212"}], "release": {"ref": "PostgreSQL 20devel source archive", "label": "20devel", "major": "20", "channel": "devel", "revision": "4d3346909b201ac1648232cf290462a7070c119326f56196f1f0253ed80fae41", "source_url": "https://ftp.postgresql.org/pub/snapshot/dev/postgresql-snapshot.tar.bz2", "source_snapshot_utc": "26-Sep-2026 20:22"}, "sources": [{"url": "https://ftp.postgresql.org/pub/snapshot/dev/postgresql-snapshot.tar.bz2", "line": 1427, "path": "src/backend/commands/explain.c", "label": "src/backend/commands/explain.c:1427", "sha256": "13402758013520451539427b5993db06d463ca11c4e2d4cc5444e82367688077", "archive_sha256": "4d3346909b201ac1648232cf290462a7070c119326f56196f1f0253ed80fae41"}, {"url": "https://ftp.postgresql.org/pub/snapshot/dev/postgresql-snapshot.tar.bz2", "line": 196, "path": "src/backend/executor/execProcnode.c", "label": "src/backend/executor/execProcnode.c:196", "sha256": "5e39b2037bed672da55104229ecc32da5abde44c26bcad01479edcfa044d09ed", "archive_sha256": "4d3346909b201ac1648232cf290462a7070c119326f56196f1f0253ed80fae41"}, {"url": "https://ftp.postgresql.org/pub/snapshot/dev/postgresql-snapshot.tar.bz2", "path": "src/backend/executor/nodeBitmapAnd.c", "label": "src/backend/executor/nodeBitmapAnd.c", "sha256": "abe3988513ba535961cc5becec9234c985cd22cfb5836bba56053854b974304d", "archive_sha256": "4d3346909b201ac1648232cf290462a7070c119326f56196f1f0253ed80fae41"}, {"url": "https://ftp.postgresql.org/pub/snapshot/dev/postgresql-snapshot.tar.bz2", "path": "src/include/nodes/plannodes.h", "label": "src/include/nodes/plannodes.h", "sha256": "7a94ed1652f0d74d50c39971d1cd3e8051dbc0d6058f31b6de71a433ca343521", "archive_sha256": "4d3346909b201ac1648232cf290462a7070c119326f56196f1f0253ed80fae41"}, {"url": "https://pg.center/docs/devel/using-explain.html#USING-EXPLAIN-CAVEATS", "path": "using-explain.html", "label": "PostgreSQL 20devel \u00b7 using-explain", "sha256": "99cfea3035876ea63f88b75ba8c964b51a32a70606544e09f769c0b60a234b31", "language": "en", "original_url": "/docs/devel/using-explain.html#USING-EXPLAIN-CAVEATS"}, {"url": "https://pg.center/docs/devel/using-explain.html#USING-EXPLAIN-BASICS", "path": "using-explain.html", "label": "PostgreSQL 20devel \u00b7 using-explain", "sha256": "99cfea3035876ea63f88b75ba8c964b51a32a70606544e09f769c0b60a234b31", "language": "en", "original_url": "/docs/devel/using-explain.html#USING-EXPLAIN-BASICS"}, {"url": "https://pg.center/docs/devel/using-explain.html#USING-EXPLAIN-ANALYZE", "path": "using-explain.html", "label": "PostgreSQL 20devel \u00b7 using-explain", "sha256": "99cfea3035876ea63f88b75ba8c964b51a32a70606544e09f769c0b60a234b31", "language": "en", "original_url": "/docs/devel/using-explain.html#USING-EXPLAIN-ANALYZE"}], "node_tag": "T_BitmapAnd", "sections": [{"title": "EXPLAIN \u540d\u79f0\u4e0e\u5c5e\u6027", "paragraphs": ["\u7ed3\u6784\u5316\u683c\u5f0f\u4f7f\u7528\u4e0a\u8ff0 Node Type\u3002\u6587\u672c\u683c\u5f0f\u540d\u79f0\u8fd8\u53ef\u80fd\u5305\u542b\u64cd\u4f5c\u3001\u7b56\u7565\u3001\u8fde\u63a5\u7c7b\u578b\u3001\u626b\u63cf\u65b9\u5411\u6216\u805a\u5408\u9636\u6bb5\u5c5e\u6027\u3002", "\u6b64\u6e90\u7801\u8bb0\u5f55\u7684\u6587\u672c\u540d\u79f0\uff1aBitmapAnd.", "\u5e76\u884c\u611f\u77e5\u4e0e\u5e76\u884c\u5b89\u5168\u662f\u4e0d\u540c\u7684\u8ba1\u5212\u5c5e\u6027\u3002\u5728\u5e76\u884c\u5de5\u4f5c\u8fdb\u7a0b\u5185\u8fd0\u884c\u7684\u8282\u70b9\u4e0d\u4e00\u5b9a\u662f\u5e76\u884c\u611f\u77e5\u8282\u70b9\u3002"]}, {"title": "\u5185\u5b58\u4e0e\u4e34\u65f6\u5b58\u50a8", "paragraphs": ["\u672c\u6b21\u62bd\u53d6\u4e0d\u4e3a\u6b64\u8282\u70b9\u8bbe\u5b9a\u7edf\u4e00\u7684\u5185\u5b58\u4e0a\u9650\u6216\u843d\u76d8\u7b56\u7565\u3002\u8bf7\u67e5\u770b\u540c\u4e00\u6784\u5efa\u7684\u5b9e\u73b0\u3001\u76f8\u5173\u8868\u8fbe\u5f0f\u6216\u63d0\u4f9b\u65b9\u3002"]}, {"title": "\u5e76\u884c\u6267\u884c\u4e0e\u8fd0\u884c\u4fe1\u606f\u91c7\u96c6", "paragraphs": ["\u4ee5\u4e0b\u6e90\u7801\u56de\u8c03\u53ef\u4ee5\u534f\u8c03\u6267\u884c\u6216\u6536\u96c6\u5de5\u4f5c\u8fdb\u7a0b\u7684\u6d4b\u91cf\u6570\u636e\u3002\u56de\u8c03\u5b58\u5728\u4e0d\u4ee3\u8868\u8be5\u8282\u70b9\u666e\u904d\u652f\u6301\u5171\u4eab\u5e76\u884c\u626b\u63cf\u6216\u5171\u4eab\u72b6\u6001\u3002", "\u6b64\u6784\u5efa\u7684\u56de\u8c03\uff1anone extracted from this node implementation."]}, {"title": "\u540c\u7248\u672c\u624b\u518c\u8bf4\u660e", "paragraphs": ["\u7531\u4e8e\u5b9e\u73b0\u4e0a\u7684\u9650\u5236\uff0cBitmapAnd \u548c BitmapOr \u8282\u70b9\u62a5\u544a\u7684\u5b9e\u9645\u884c\u6570\u59cb\u7ec8\u4e3a\u96f6\u3002"]}, {"title": "\u672c\u7248\u624b\u518c\u4e2d\u7684\u793a\u4f8b", "blocks": [{"code": "EXPLAIN SELECT * FROM tenk1 WHERE unique1 < 100 AND unique2 > 9000;\n\n QUERY PLAN\n-------------------------------------------------------------------------------------\n Bitmap Heap Scan on tenk1 (cost=25.07..60.11 rows=10 width=244)\n Recheck Cond: ((unique1 < 100) AND (unique2 > 9000))\n -> BitmapAnd (cost=25.07..25.07 rows=10 width=0)\n -> Bitmap Index Scan on tenk1_unique1 (cost=0.00..5.04 rows=100 width=0)\n Index Cond: (unique1 < 100)\n -> Bitmap Index Scan on tenk1_unique2 (cost=0.00..19.78 rows=999 width=0)\n Index Cond: (unique2 > 9000)", "source": {"url": "/docs/devel/using-explain.html#USING-EXPLAIN-BASICS", "path": "using-explain.html", "label": "PostgreSQL 20devel \u00b7 using-explain", "sha256": "99cfea3035876ea63f88b75ba8c964b51a32a70606544e09f769c0b60a234b31"}, "paragraphs": ["\u793a\u4f8b\u6458\u81ea PostgreSQL 20devel \u624b\u518c\uff1b\u672c\u767e\u79d1\u672a\u5b9e\u9645\u6267\u884c\u6b64\u793a\u4f8b\u3002", "\u5982\u679c WHERE \u5f15\u7528\u7684\u591a\u4e2a\u5217\u4e0a\u5206\u522b\u5efa\u6709\u7d22\u5f15\uff0c\u89c4\u5212\u5668\u53ef\u80fd\u9009\u62e9\u7528 AND \u6216 OR \u7ec4\u5408\u8fd9\u4e9b\u7d22\u5f15\uff1a"]}, {"code": "EXPLAIN (ANALYZE, BUFFERS OFF) SELECT * FROM tenk1 WHERE unique1 < 100 AND unique2 > 9000;\n\n QUERY PLAN\n---------------------------------------------------------------------------------------------------------------------------------\n Bitmap Heap Scan on tenk1 (cost=25.07..60.11 rows=10 width=244) (actual time=0.105..0.114 rows=10.00 loops=1)\n Recheck Cond: ((unique1 < 100) AND (unique2 > 9000))\n Heap Blocks: exact=10\n -> BitmapAnd (cost=25.07..25.07 rows=10 width=0) (actual time=0.100..0.101 rows=0.00 loops=1)\n -> Bitmap Index Scan on tenk1_unique1 (cost=0.00..5.04 rows=100 width=0) (actual time=0.027..0.027 rows=100.00 loops=1)\n Index Cond: (unique1 < 100)\n Index Searches: 1\n -> Bitmap Index Scan on tenk1_unique2 (cost=0.00..19.78 rows=999 width=0) (actual time=0.070..0.070 rows=999.00 loops=1)\n Index Cond: (unique2 > 9000)\n Index Searches: 1\n Planning Time: 0.162 ms\n Execution Time: 0.143 ms", "source": {"url": "/docs/devel/using-explain.html#USING-EXPLAIN-ANALYZE", "path": "using-explain.html", "label": "PostgreSQL 20devel \u00b7 using-explain", "sha256": "99cfea3035876ea63f88b75ba8c964b51a32a70606544e09f769c0b60a234b31"}, "paragraphs": ["\u793a\u4f8b\u6458\u81ea PostgreSQL 20devel \u624b\u518c\uff1b\u672c\u767e\u79d1\u672a\u5b9e\u9645\u6267\u884c\u6b64\u793a\u4f8b\u3002", "EXPLAIN \u6709\u4e00\u4e2a BUFFERS \u9009\u9879\uff0c\u53ef\u4e3a\u7ed9\u5b9a\u67e5\u8be2\u5728\u89c4\u5212\u548c\u6267\u884c\u671f\u95f4\u6267\u884c\u7684 I/O \u64cd\u4f5c\u63d0\u4f9b\u66f4\u8be6\u7ec6\u7684\u4fe1\u606f\u3002\u663e\u793a\u51fa\u6765\u7684\u7f13\u51b2\u533a\u6570\u5b57\uff0c\u662f\u8be5\u8282\u70b9\u53ca\u5176\u6240\u6709\u5b50\u8282\u70b9\u6240\u547d\u4e2d\u7684\u3001\u8bfb\u53d6\u7684\u3001\u5f04\u810f\u7684\u548c\u5199\u51fa\u7684\u975e\u53bb\u91cd\u7f13\u51b2\u533a\u603b\u6570\u3002 ANALYZE \u9009\u9879\u4f1a\u9690\u5f0f\u542f\u7528 BUFFERS \u3002\u5982\u679c\u4e0d\u5e0c\u671b\u5982\u6b64\uff0c\u4e5f\u53ef\u4ee5\u663e\u5f0f\u5173\u95ed BUFFERS \uff1a"]}]}, {"title": "\u6267\u884c\u5668\u5b9e\u73b0\u8bf4\u660e", "paragraphs": ["\u8bf4\u660e\uff1aBitmapAnd \u4e0d\u4f7f\u7528\u5de6\u53f3\u5b50\u6811\uff0c\u800c\u50cf Append \u4e00\u6837\u7ef4\u62a4\u5b50\u8ba1\u5212\u5217\u8868\u3002\u4e0d\u8fc7\u5176\u903b\u8f91\u6bd4 Append \u7b80\u5355\u5f97\u591a\uff0c\u56e0\u4e3a\u65e0\u9700\u5904\u7406\u6b63\u5411\u6216\u53cd\u5411\u6267\u884c\u3002", "\u5bf9\u6bcf\u4e2a\u5f85\u6267\u884c\u8ba1\u5212\u8c03\u7528 ExecInitNode\uff0c\u5e76\u5c06\u7ed3\u679c\u4fdd\u5b58\u5230 bitmapplanstates \u6570\u7ec4\u3002", "BitmapAnd \u8ba1\u5212\u6ca1\u6709\u8868\u8fbe\u5f0f\u4e0a\u4e0b\u6587\uff0c\u56e0\u4e3a\u5b83\u4eec\u4ece\u4e0d\u8c03\u7528 ExecQual \u6216 ExecProject\uff0c\u4e5f\u4e0d\u9700\u8981\u5143\u7ec4\u69fd\u3002", "\u5982\u679c\u5728\u4efb\u4f55\u9636\u6bb5\u5f97\u5230\u5b8c\u5168\u4e3a\u7a7a\u7684\u4f4d\u56fe\uff0c\u5c31\u53ef\u4ee5\u76f4\u63a5\u9000\u51fa\uff0c\u65e0\u9700\u6267\u884c\u5269\u4f59\u5b50\u8ba1\u5212\uff0c\u56e0\u4e3a\u518d\u8fdb\u884c AND \u8fd0\u7b97\u4e5f\u4e0d\u4f1a\u6539\u53d8\u7ed3\u679c\u3002\uff08\u6ce8\u610f\uff1aindxpath.c \u6309\u9009\u62e9\u7387\u5bf9\u5b50\u8ba1\u5212\u6392\u5e8f\uff0c\u5e94\u5f53\u80fd\u63d0\u9ad8\u51fa\u73b0\u8fd9\u79cd\u60c5\u51b5\u7684\u6982\u7387\u3002\uff09", "ExecReScan \u4e0d\u77e5\u9053\u5f53\u524d\u8282\u70b9\u7684\u5b50\u8ba1\u5212\uff0c\u56e0\u6b64\u5fc5\u987b\u81ea\u884c\u901a\u77e5\u5b50\u8ba1\u5212\u54ea\u4e9b\u53c2\u6570\u53d1\u751f\u4e86\u53d8\u5316\u3002"]}, {"code": "case T_BitmapAnd:\n\t\t\tpname = sname = \"BitmapAnd\";\n\t\t\tbreak;", "title": "\u6838\u5fc3\u6e90\u7801\u4e2d\u7684 EXPLAIN \u6807\u8bc6"}], "strategies": [], "description": ["\u5bf9\u5404\u5b50\u8ba1\u5212\u4ea7\u751f\u7684\u4f4d\u56fe\u6c42\u4ea4\u96c6\u3002"], "localization": {"status": "complete", "sources": [{"url": "/docs/devel/using-explain.html", "method": "same-major semantic node", "sha256": "2744ee0e88d132c504bf5e102765edaabd393eb12c59294093db6d90b26dd65c", "language": "zh", "matched_nodes": ["#USING-EXPLAIN/div[8]/p[27]"]}], "language": "zh", "original_text": {"/summary": "Intersects bitmaps produced by its child plans.", "/category": "Bitmap", "/versions/20/description/0": "Intersects bitmaps produced by its child plans.", "/versions/20/facts/0/label": "Core node tag", "/versions/20/facts/1/label": "Structured EXPLAIN Node Type", "/versions/20/facts/2/label": "Inputs", "/versions/20/facts/2/value": "Bitmap-producing child plans", "/versions/20/facts/3/label": "Output", "/versions/20/facts/3/value": "Tuple-location bitmap, not a tuple stream", "/versions/20/facts/4/label": "Executor initializer", "/versions/20/facts/5/label": "Memory mechanism", "/versions/20/tables/0/title": "EXPLAIN labels in this source build", "/versions/20/related/1/label": "Using EXPLAIN", "/versions/20/related/2/label": "Parallel plans", "/versions/20/sections/0/title": "EXPLAIN names and attributes", "/versions/20/sections/1/title": "Memory and temporary storage", "/versions/20/sections/2/title": "Parallel execution and instrumentation", "/versions/20/sections/3/title": "Same-version manual discussion", "/versions/20/sections/4/title": "Examples from this manual build", "/versions/20/sections/5/title": "Executor implementation notes", "/versions/20/sections/6/title": "EXPLAIN identity in core source", "/versions/20/memory/description": "This extraction does not assign a universal memory limit or spill policy to this node. Inspect the same-build implementation and its expressions or provider.", "/versions/20/sections/0/paragraphs/0": "Structured formats use the Node Type above. Text-format spellings can also include operation, strategy, join type, scan direction or aggregation-stage attributes.", "/versions/20/sections/0/paragraphs/1": "Text names recorded by this source: BitmapAnd.", "/versions/20/sections/0/paragraphs/2": "Parallel-aware and parallel-safe are different plan properties. A node running inside a parallel worker is not necessarily a parallel-aware node.", "/versions/20/sections/1/paragraphs/0": "This extraction does not assign a universal memory limit or spill policy to this node. Inspect the same-build implementation and its expressions or provider.", "/versions/20/sections/2/paragraphs/0": "The source callbacks below can coordinate execution or collect worker instrumentation. Their presence is not a blanket claim that this node supports a shared parallel scan or shared state.", "/versions/20/sections/2/paragraphs/1": "Callbacks in this build: none extracted from this node implementation.", "/versions/20/sections/3/paragraphs/0": "BitmapAnd and BitmapOr nodes always report their actual row counts as zero, due to implementation limitations.", "/versions/20/sections/5/paragraphs/0": "NOTES BitmapAnd nodes don't make use of their left and right subtrees, rather they maintain a list of subplans, much like Append nodes. The logic is much simpler than Append, however, since we needn't cope with forward/backward execution.", "/versions/20/sections/5/paragraphs/1": "call ExecInitNode on each of the plans to be executed and save the results into the array \"bitmapplanstates\".", "/versions/20/sections/5/paragraphs/2": "BitmapAnd plans don't have expression contexts because they never call ExecQual or ExecProject. They don't need any tuple slots either.", "/versions/20/sections/5/paragraphs/3": "If at any stage we have a completely empty bitmap, we can fall out without evaluating the remaining subplans, since ANDing them can no longer change the result. (Note: the fact that indxpath.c orders the subplans by selectivity should make this case more likely to occur.)", "/versions/20/sections/5/paragraphs/4": "ExecReScan doesn't know about my subplans, so I have to do changed-parameter signaling myself.", "/versions/20/tables/0/columns/0/label": "Text-format label", "/versions/20/tables/0/columns/1/label": "Structured node identity", "/versions/20/sections/4/blocks/0/paragraphs/0": "Example copied from the PostgreSQL 20devel manual; it was not executed for this collection.", "/versions/20/sections/4/blocks/0/paragraphs/1": "If there are separate indexes on several of the columns referenced in WHERE , the planner might choose to use an AND or OR combination of the indexes:", "/versions/20/sections/4/blocks/1/paragraphs/0": "Example copied from the PostgreSQL 20devel manual; it was not executed for this collection.", "/versions/20/sections/4/blocks/1/paragraphs/1": "EXPLAIN has a BUFFERS option which provides additional detail about I/O operations performed during the planning and execution of the given query. The buffer numbers displayed show the count of the non-distinct buffers hit, read, dirtied, and written for the given node and all of its child nodes. The ANALYZE option implicitly enables the BUFFERS option. If this is undesired, BUFFERS may be explicitly disabled:"}, "fallback_fields": [], "source_language": "en", "original_snapshot_sha256": "5934ce0b458ed79b50236b7fe0e8692114df31f5deb5034d53fcb51366415cc1"}, "evidence_kind": "source and documentation", "explain_names": ["BitmapAnd"], "partial_modes": [], "comparison_data": {"node_tag": "T_BitmapAnd", "strategies": [], "text_names": ["BitmapAnd"], "initializer": "ExecInitBitmapAnd", "partial_modes": [], "memory_mechanism": "unclassified", "parallel_callbacks": []}, "comparison_hash": "ffac2f4c3c78a9e2f88eb2c2de755f5a69e40f1ac6d7e9bcb4ed08615c9cb803", "explain_prefixes": ["Parallel", "Async"], "runtime_verified": false, "source_inventory": {"explain": "src/backend/commands/explain.c", "executor": "src/backend/executor/execProcnode.c", "implementation": "src/backend/executor/nodeBitmapAnd.c"}, "parallel_callbacks": []}}}, "snapshot": {"facts": [{"label": "\u6838\u5fc3\u8282\u70b9\u6807\u7b7e", "value": "T_BitmapAnd"}, {"label": "\u7ed3\u6784\u5316 EXPLAIN \u8282\u70b9\u7c7b\u578b", "value": "BitmapAnd"}, {"label": "\u8f93\u5165", "value": "\u4ea7\u751f\u4f4d\u56fe\u7684\u5b50\u8ba1\u5212"}, {"label": "\u8f93\u51fa", "value": "\u5143\u7ec4\u4f4d\u7f6e\u4f4d\u56fe\uff0c\u4e0d\u662f\u5143\u7ec4\u6d41"}, {"label": "\u6267\u884c\u5668\u521d\u59cb\u5316\u51fd\u6570", "value": "ExecInitBitmapAnd"}, {"label": "\u5185\u5b58\u673a\u5236", "value": "unclassified"}], "memory": {"evidence": [{"url": "https://ftp.postgresql.org/pub/source/v18.6/postgresql-18.6.tar.bz2", "path": "src/backend/executor/nodeBitmapAnd.c", "label": "src/backend/executor/nodeBitmapAnd.c", "sha256": "ec359e3996322cd5f16aab61f23a38e26dae336bbcea4db735a6a70e0ecc89dd", "archive_sha256": "555610c24d53e4316da5b7d3fc25c279d96856d5e0e23ee308c328c5fa881d9f"}], "mechanism": "unclassified", "description": "\u672c\u6b21\u62bd\u53d6\u4e0d\u4e3a\u6b64\u8282\u70b9\u8bbe\u5b9a\u7edf\u4e00\u7684\u5185\u5b58\u4e0a\u9650\u6216\u843d\u76d8\u7b56\u7565\u3002\u8bf7\u67e5\u770b\u540c\u4e00\u6784\u5efa\u7684\u5b9e\u73b0\u3001\u76f8\u5173\u8868\u8fbe\u5f0f\u6216\u63d0\u4f9b\u65b9\u3002", "source_notes": []}, "tables": [{"key": "explain-labels", "rows": [{"label": "BitmapAnd", "identity": "BitmapAnd"}], "title": "\u672c\u6784\u5efa\u4e2d\u7684 EXPLAIN \u6807\u7b7e", "columns": [{"key": "label", "label": "\u6587\u672c\u683c\u5f0f\u6807\u7b7e"}, {"key": "identity", "label": "\u7ed3\u6784\u5316\u8282\u70b9\u6807\u8bc6"}]}], "related": [{"url": "/wiki/sql/explain/?v=18", "label": "EXPLAIN"}, {"url": "/docs/18/using-explain.html", "label": "\u4f7f\u7528 EXPLAIN"}, {"url": "/docs/18/parallel-plans.html", "label": "\u5e76\u884c\u8ba1\u5212"}], "release": {"ref": "PostgreSQL 18.6 source archive", "label": "18.6", "major": "18", "channel": "stable", "revision": "555610c24d53e4316da5b7d3fc25c279d96856d5e0e23ee308c328c5fa881d9f", "source_url": "https://ftp.postgresql.org/pub/source/v18.6/postgresql-18.6.tar.bz2", "source_snapshot_utc": ""}, "sources": [{"url": "https://ftp.postgresql.org/pub/source/v18.6/postgresql-18.6.tar.bz2", "line": 1415, "path": "src/backend/commands/explain.c", "label": "src/backend/commands/explain.c:1415", "sha256": "34c86d6070224a0e981efef51f79101d6d505e5874f1684ace183034bab14bb4", "archive_sha256": "555610c24d53e4316da5b7d3fc25c279d96856d5e0e23ee308c328c5fa881d9f"}, {"url": "https://ftp.postgresql.org/pub/source/v18.6/postgresql-18.6.tar.bz2", "line": 196, "path": "src/backend/executor/execProcnode.c", "label": "src/backend/executor/execProcnode.c:196", "sha256": "f8a06a3f539077249b20664b2812433db6d7bd12b2c0ca633525db43d06f112a", "archive_sha256": "555610c24d53e4316da5b7d3fc25c279d96856d5e0e23ee308c328c5fa881d9f"}, {"url": "https://ftp.postgresql.org/pub/source/v18.6/postgresql-18.6.tar.bz2", "path": "src/backend/executor/nodeBitmapAnd.c", "label": "src/backend/executor/nodeBitmapAnd.c", "sha256": "ec359e3996322cd5f16aab61f23a38e26dae336bbcea4db735a6a70e0ecc89dd", "archive_sha256": "555610c24d53e4316da5b7d3fc25c279d96856d5e0e23ee308c328c5fa881d9f"}, {"url": "https://ftp.postgresql.org/pub/source/v18.6/postgresql-18.6.tar.bz2", "path": "src/include/nodes/plannodes.h", "label": "src/include/nodes/plannodes.h", "sha256": "52422b327a8049fbbb20d8b96008a0fc0a6fafa60f7eff3c695d5b2e83830120", "archive_sha256": "555610c24d53e4316da5b7d3fc25c279d96856d5e0e23ee308c328c5fa881d9f"}, {"url": "https://pg.center/docs/18/using-explain.html#USING-EXPLAIN-CAVEATS", "path": "using-explain.html", "label": "PostgreSQL 18.6 \u00b7 using-explain", "sha256": "60040c30180093418a0affe56dd27dff9df2504b705b38039589e458bf5c31ed", "language": "en", "original_url": "/docs/18/using-explain.html#USING-EXPLAIN-CAVEATS"}, {"url": "https://pg.center/docs/18/using-explain.html#USING-EXPLAIN-BASICS", "path": "using-explain.html", "label": "PostgreSQL 18.6 \u00b7 using-explain", "sha256": "60040c30180093418a0affe56dd27dff9df2504b705b38039589e458bf5c31ed", "language": "en", "original_url": "/docs/18/using-explain.html#USING-EXPLAIN-BASICS"}, {"url": "https://pg.center/docs/18/using-explain.html#USING-EXPLAIN-ANALYZE", "path": "using-explain.html", "label": "PostgreSQL 18.6 \u00b7 using-explain", "sha256": "60040c30180093418a0affe56dd27dff9df2504b705b38039589e458bf5c31ed", "language": "en", "original_url": "/docs/18/using-explain.html#USING-EXPLAIN-ANALYZE"}], "node_tag": "T_BitmapAnd", "sections": [{"title": "EXPLAIN \u540d\u79f0\u4e0e\u5c5e\u6027", "paragraphs": ["\u7ed3\u6784\u5316\u683c\u5f0f\u4f7f\u7528\u4e0a\u8ff0 Node Type\u3002\u6587\u672c\u683c\u5f0f\u540d\u79f0\u8fd8\u53ef\u80fd\u5305\u542b\u64cd\u4f5c\u3001\u7b56\u7565\u3001\u8fde\u63a5\u7c7b\u578b\u3001\u626b\u63cf\u65b9\u5411\u6216\u805a\u5408\u9636\u6bb5\u5c5e\u6027\u3002", "\u6b64\u6e90\u7801\u8bb0\u5f55\u7684\u6587\u672c\u540d\u79f0\uff1aBitmapAnd.", "\u5e76\u884c\u611f\u77e5\u4e0e\u5e76\u884c\u5b89\u5168\u662f\u4e0d\u540c\u7684\u8ba1\u5212\u5c5e\u6027\u3002\u5728\u5e76\u884c\u5de5\u4f5c\u8fdb\u7a0b\u5185\u8fd0\u884c\u7684\u8282\u70b9\u4e0d\u4e00\u5b9a\u662f\u5e76\u884c\u611f\u77e5\u8282\u70b9\u3002"]}, {"title": "\u5185\u5b58\u4e0e\u4e34\u65f6\u5b58\u50a8", "paragraphs": ["\u672c\u6b21\u62bd\u53d6\u4e0d\u4e3a\u6b64\u8282\u70b9\u8bbe\u5b9a\u7edf\u4e00\u7684\u5185\u5b58\u4e0a\u9650\u6216\u843d\u76d8\u7b56\u7565\u3002\u8bf7\u67e5\u770b\u540c\u4e00\u6784\u5efa\u7684\u5b9e\u73b0\u3001\u76f8\u5173\u8868\u8fbe\u5f0f\u6216\u63d0\u4f9b\u65b9\u3002"]}, {"title": "\u5e76\u884c\u6267\u884c\u4e0e\u8fd0\u884c\u4fe1\u606f\u91c7\u96c6", "paragraphs": ["\u4ee5\u4e0b\u6e90\u7801\u56de\u8c03\u53ef\u4ee5\u534f\u8c03\u6267\u884c\u6216\u6536\u96c6\u5de5\u4f5c\u8fdb\u7a0b\u7684\u6d4b\u91cf\u6570\u636e\u3002\u56de\u8c03\u5b58\u5728\u4e0d\u4ee3\u8868\u8be5\u8282\u70b9\u666e\u904d\u652f\u6301\u5171\u4eab\u5e76\u884c\u626b\u63cf\u6216\u5171\u4eab\u72b6\u6001\u3002", "\u6b64\u6784\u5efa\u7684\u56de\u8c03\uff1anone extracted from this node implementation."]}, {"title": "\u540c\u7248\u672c\u624b\u518c\u8bf4\u660e", "paragraphs": ["\u7531\u4e8e\u5b9e\u73b0\u4e0a\u7684\u9650\u5236\uff0cBitmapAnd \u548c BitmapOr \u8282\u70b9\u62a5\u544a\u7684\u5b9e\u9645\u884c\u6570\u59cb\u7ec8\u4e3a\u96f6\u3002"]}, {"title": "\u672c\u7248\u624b\u518c\u4e2d\u7684\u793a\u4f8b", "blocks": [{"code": "EXPLAIN SELECT * FROM tenk1 WHERE unique1 < 100 AND unique2 > 9000;\n\n QUERY PLAN\n-------------------------------------------------------------------------------------\n Bitmap Heap Scan on tenk1 (cost=25.07..60.11 rows=10 width=244)\n Recheck Cond: ((unique1 < 100) AND (unique2 > 9000))\n -> BitmapAnd (cost=25.07..25.07 rows=10 width=0)\n -> Bitmap Index Scan on tenk1_unique1 (cost=0.00..5.04 rows=100 width=0)\n Index Cond: (unique1 < 100)\n -> Bitmap Index Scan on tenk1_unique2 (cost=0.00..19.78 rows=999 width=0)\n Index Cond: (unique2 > 9000)", "source": {"url": "/docs/18/using-explain.html#USING-EXPLAIN-BASICS", "path": "using-explain.html", "label": "PostgreSQL 18.6 \u00b7 using-explain", "sha256": "60040c30180093418a0affe56dd27dff9df2504b705b38039589e458bf5c31ed"}, "paragraphs": ["\u793a\u4f8b\u6458\u81ea PostgreSQL 18.6 \u624b\u518c\uff1b\u672c\u767e\u79d1\u672a\u5b9e\u9645\u6267\u884c\u6b64\u793a\u4f8b\u3002", "\u5982\u679c WHERE \u5f15\u7528\u7684\u591a\u4e2a\u5217\u4e0a\u5206\u522b\u5efa\u6709\u7d22\u5f15\uff0c\u89c4\u5212\u5668\u53ef\u80fd\u9009\u62e9\u7528 AND \u6216 OR \u7ec4\u5408\u8fd9\u4e9b\u7d22\u5f15\uff1a"]}, {"code": "EXPLAIN (ANALYZE, BUFFERS OFF) SELECT * FROM tenk1 WHERE unique1 < 100 AND unique2 > 9000;\n\n QUERY PLAN\n---------------------------------------------------------------------------------------------------------------------------------\n Bitmap Heap Scan on tenk1 (cost=25.07..60.11 rows=10 width=244) (actual time=0.105..0.114 rows=10.00 loops=1)\n Recheck Cond: ((unique1 < 100) AND (unique2 > 9000))\n Heap Blocks: exact=10\n -> BitmapAnd (cost=25.07..25.07 rows=10 width=0) (actual time=0.100..0.101 rows=0.00 loops=1)\n -> Bitmap Index Scan on tenk1_unique1 (cost=0.00..5.04 rows=100 width=0) (actual time=0.027..0.027 rows=100.00 loops=1)\n Index Cond: (unique1 < 100)\n Index Searches: 1\n -> Bitmap Index Scan on tenk1_unique2 (cost=0.00..19.78 rows=999 width=0) (actual time=0.070..0.070 rows=999.00 loops=1)\n Index Cond: (unique2 > 9000)\n Index Searches: 1\n Planning Time: 0.162 ms\n Execution Time: 0.143 ms", "source": {"url": "/docs/18/using-explain.html#USING-EXPLAIN-ANALYZE", "path": "using-explain.html", "label": "PostgreSQL 18.6 \u00b7 using-explain", "sha256": "60040c30180093418a0affe56dd27dff9df2504b705b38039589e458bf5c31ed"}, "paragraphs": ["\u793a\u4f8b\u6458\u81ea PostgreSQL 18.6 \u624b\u518c\uff1b\u672c\u767e\u79d1\u672a\u5b9e\u9645\u6267\u884c\u6b64\u793a\u4f8b\u3002", "EXPLAIN \u6709\u4e00\u4e2a BUFFERS \u9009\u9879\uff0c\u53ef\u4e3a\u7ed9\u5b9a\u67e5\u8be2\u5728\u89c4\u5212\u548c\u6267\u884c\u671f\u95f4\u6267\u884c\u7684 I/O \u64cd\u4f5c\u63d0\u4f9b\u66f4\u8be6\u7ec6\u7684\u4fe1\u606f\u3002\u663e\u793a\u51fa\u6765\u7684\u7f13\u51b2\u533a\u6570\u5b57\uff0c\u662f\u8be5\u8282\u70b9\u53ca\u5176\u6240\u6709\u5b50\u8282\u70b9\u6240\u547d\u4e2d\u7684\u3001\u8bfb\u53d6\u7684\u3001\u5f04\u810f\u7684\u548c\u5199\u51fa\u7684\u975e\u53bb\u91cd\u7f13\u51b2\u533a\u603b\u6570\u3002 ANALYZE \u9009\u9879\u4f1a\u9690\u5f0f\u542f\u7528 BUFFERS \u3002\u5982\u679c\u4e0d\u5e0c\u671b\u5982\u6b64\uff0c\u4e5f\u53ef\u4ee5\u663e\u5f0f\u5173\u95ed BUFFERS \uff1a"]}]}, {"title": "\u6267\u884c\u5668\u5b9e\u73b0\u8bf4\u660e", "paragraphs": ["\u8bf4\u660e\uff1aBitmapAnd \u4e0d\u4f7f\u7528\u5de6\u53f3\u5b50\u6811\uff0c\u800c\u50cf Append \u4e00\u6837\u7ef4\u62a4\u5b50\u8ba1\u5212\u5217\u8868\u3002\u4e0d\u8fc7\u5176\u903b\u8f91\u6bd4 Append \u7b80\u5355\u5f97\u591a\uff0c\u56e0\u4e3a\u65e0\u9700\u5904\u7406\u6b63\u5411\u6216\u53cd\u5411\u6267\u884c\u3002", "\u5bf9\u6bcf\u4e2a\u5f85\u6267\u884c\u8ba1\u5212\u8c03\u7528 ExecInitNode\uff0c\u5e76\u5c06\u7ed3\u679c\u4fdd\u5b58\u5230 bitmapplanstates \u6570\u7ec4\u3002", "BitmapAnd \u8ba1\u5212\u6ca1\u6709\u8868\u8fbe\u5f0f\u4e0a\u4e0b\u6587\uff0c\u56e0\u4e3a\u5b83\u4eec\u4ece\u4e0d\u8c03\u7528 ExecQual \u6216 ExecProject\uff0c\u4e5f\u4e0d\u9700\u8981\u5143\u7ec4\u69fd\u3002", "\u5982\u679c\u5728\u4efb\u4f55\u9636\u6bb5\u5f97\u5230\u5b8c\u5168\u4e3a\u7a7a\u7684\u4f4d\u56fe\uff0c\u5c31\u53ef\u4ee5\u76f4\u63a5\u9000\u51fa\uff0c\u65e0\u9700\u6267\u884c\u5269\u4f59\u5b50\u8ba1\u5212\uff0c\u56e0\u4e3a\u518d\u8fdb\u884c AND \u8fd0\u7b97\u4e5f\u4e0d\u4f1a\u6539\u53d8\u7ed3\u679c\u3002\uff08\u6ce8\u610f\uff1aindxpath.c \u6309\u9009\u62e9\u7387\u5bf9\u5b50\u8ba1\u5212\u6392\u5e8f\uff0c\u5e94\u5f53\u80fd\u63d0\u9ad8\u51fa\u73b0\u8fd9\u79cd\u60c5\u51b5\u7684\u6982\u7387\u3002\uff09", "ExecReScan \u4e0d\u77e5\u9053\u5f53\u524d\u8282\u70b9\u7684\u5b50\u8ba1\u5212\uff0c\u56e0\u6b64\u5fc5\u987b\u81ea\u884c\u901a\u77e5\u5b50\u8ba1\u5212\u54ea\u4e9b\u53c2\u6570\u53d1\u751f\u4e86\u53d8\u5316\u3002"]}, {"code": "case T_BitmapAnd:\n\t\t\tpname = sname = \"BitmapAnd\";\n\t\t\tbreak;", "title": "\u6838\u5fc3\u6e90\u7801\u4e2d\u7684 EXPLAIN \u6807\u8bc6"}], "strategies": [], "description": ["\u5bf9\u5404\u5b50\u8ba1\u5212\u4ea7\u751f\u7684\u4f4d\u56fe\u6c42\u4ea4\u96c6\u3002"], "localization": {"status": "complete", "sources": [{"url": "/docs/18/using-explain.html", "method": "same-major semantic node", "sha256": "b8835ec9adbc70ec150667a6b5443f8d298222dc0cc8c2bd1abb1c1d64895904", "language": "zh", "matched_nodes": ["#USING-EXPLAIN/div[8]/p[24]"]}], "language": "zh", "original_text": {"/versions/18/description/0": "Intersects bitmaps produced by its child plans.", "/versions/18/facts/0/label": "Core node tag", "/versions/18/facts/1/label": "Structured EXPLAIN Node Type", "/versions/18/facts/2/label": "Inputs", "/versions/18/facts/2/value": "Bitmap-producing child plans", "/versions/18/facts/3/label": "Output", "/versions/18/facts/3/value": "Tuple-location bitmap, not a tuple stream", "/versions/18/facts/4/label": "Executor initializer", "/versions/18/facts/5/label": "Memory mechanism", "/versions/18/tables/0/title": "EXPLAIN labels in this source build", "/versions/18/related/1/label": "Using EXPLAIN", "/versions/18/related/2/label": "Parallel plans", "/versions/18/sections/0/title": "EXPLAIN names and attributes", "/versions/18/sections/1/title": "Memory and temporary storage", "/versions/18/sections/2/title": "Parallel execution and instrumentation", "/versions/18/sections/3/title": "Same-version manual discussion", "/versions/18/sections/4/title": "Examples from this manual build", "/versions/18/sections/5/title": "Executor implementation notes", "/versions/18/sections/6/title": "EXPLAIN identity in core source", "/versions/18/memory/description": "This extraction does not assign a universal memory limit or spill policy to this node. Inspect the same-build implementation and its expressions or provider.", "/versions/18/sections/0/paragraphs/0": "Structured formats use the Node Type above. Text-format spellings can also include operation, strategy, join type, scan direction or aggregation-stage attributes.", "/versions/18/sections/0/paragraphs/1": "Text names recorded by this source: BitmapAnd.", "/versions/18/sections/0/paragraphs/2": "Parallel-aware and parallel-safe are different plan properties. A node running inside a parallel worker is not necessarily a parallel-aware node.", "/versions/18/sections/1/paragraphs/0": "This extraction does not assign a universal memory limit or spill policy to this node. Inspect the same-build implementation and its expressions or provider.", "/versions/18/sections/2/paragraphs/0": "The source callbacks below can coordinate execution or collect worker instrumentation. Their presence is not a blanket claim that this node supports a shared parallel scan or shared state.", "/versions/18/sections/2/paragraphs/1": "Callbacks in this build: none extracted from this node implementation.", "/versions/18/sections/3/paragraphs/0": "BitmapAnd and BitmapOr nodes always report their actual row counts as zero, due to implementation limitations.", "/versions/18/sections/5/paragraphs/0": "NOTES BitmapAnd nodes don't make use of their left and right subtrees, rather they maintain a list of subplans, much like Append nodes. The logic is much simpler than Append, however, since we needn't cope with forward/backward execution.", "/versions/18/sections/5/paragraphs/1": "call ExecInitNode on each of the plans to be executed and save the results into the array \"bitmapplanstates\".", "/versions/18/sections/5/paragraphs/2": "BitmapAnd plans don't have expression contexts because they never call ExecQual or ExecProject. They don't need any tuple slots either.", "/versions/18/sections/5/paragraphs/3": "If at any stage we have a completely empty bitmap, we can fall out without evaluating the remaining subplans, since ANDing them can no longer change the result. (Note: the fact that indxpath.c orders the subplans by selectivity should make this case more likely to occur.)", "/versions/18/sections/5/paragraphs/4": "ExecReScan doesn't know about my subplans, so I have to do changed-parameter signaling myself.", "/versions/18/tables/0/columns/0/label": "Text-format label", "/versions/18/tables/0/columns/1/label": "Structured node identity", "/versions/18/sections/4/blocks/0/paragraphs/0": "Example copied from the PostgreSQL 18.6 manual; it was not executed for this collection.", "/versions/18/sections/4/blocks/0/paragraphs/1": "If there are separate indexes on several of the columns referenced in WHERE , the planner might choose to use an AND or OR combination of the indexes:", "/versions/18/sections/4/blocks/1/paragraphs/0": "Example copied from the PostgreSQL 18.6 manual; it was not executed for this collection.", "/versions/18/sections/4/blocks/1/paragraphs/1": "EXPLAIN has a BUFFERS option which provides additional detail about I/O operations performed during the planning and execution of the given query. The buffer numbers displayed show the count of the non-distinct buffers hit, read, dirtied, and written for the given node and all of its child nodes. The ANALYZE option implicitly enables the BUFFERS option. If this is undesired, BUFFERS may be explicitly disabled:"}, "fallback_fields": [], "source_language": "en", "original_snapshot_sha256": "bba8a825b70e79bd2c74f204779852f7a3d89f07c47e58a4f951c9e386c477d1"}, "evidence_kind": "source and documentation", "explain_names": ["BitmapAnd"], "partial_modes": [], "comparison_data": {"node_tag": "T_BitmapAnd", "strategies": [], "text_names": ["BitmapAnd"], "initializer": "ExecInitBitmapAnd", "partial_modes": [], "memory_mechanism": "unclassified", "parallel_callbacks": []}, "comparison_hash": "ffac2f4c3c78a9e2f88eb2c2de755f5a69e40f1ac6d7e9bcb4ed08615c9cb803", "explain_prefixes": ["Parallel", "Async"], "runtime_verified": false, "source_inventory": {"explain": "src/backend/commands/explain.c", "executor": "src/backend/executor/execProcnode.c", "implementation": "src/backend/executor/nodeBitmapAnd.c"}, "parallel_callbacks": []}, "comparison": {"left": "17", "right": "18", "status": "unchanged", "diff": ""}}