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In any case, we'll use the index tuple not the heap tuple as the data source.","Note on Memory Ordering Effects: visibilitymap_get_status does not lock the visibility map buffer, and therefore the result we read here could be slightly stale. However, it can't be stale enough to matter."],"title":"Executor implementation notes"},{"code":"case T_IndexOnlyScan:\n\t\t\tpname = sname = \"Index Only Scan\";\n\t\t\tbreak;","title":"EXPLAIN identity in core 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suffice.\u003c/p\u003e","SourceRevision":"555610c24d53e4316da5b7d3fc25c279d96856d5e0e23ee308c328c5fa881d9f","ContentHash":"213c9bc35ee0182fc346fcecc61380d394e6091b775a06f3897321932a2f20c9","Payload":{"description":["Uses index values for the result and checks tuple visibility, visiting the heap when the visibility map does not suffice."],"related":[{"label":"EXPLAIN","url":"/wiki/sql/explain/?v=18"},{"label":"Using EXPLAIN","url":"/docs/18/using-explain.html"},{"label":"Parallel plans","url":"/docs/18/parallel-plans.html"},{"label":"enable_indexonlyscan","url":"/wiki/guc/enable_indexonlyscan/?v=18"},{"label":"random_page_cost","url":"/wiki/guc/random_page_cost/?v=18"},{"label":"Index AM","url":"/wiki/indexam/?v=18"}],"sections":[{"paragraphs":["Structured formats use the Node Type above. Text-format spellings can also include operation, strategy, join type, scan direction or aggregation-stage attributes.","Text names recorded by this source: Index Only Scan.","Parallel-aware and parallel-safe are different plan properties. A node running inside a parallel worker is not necessarily a parallel-aware node."],"title":"EXPLAIN names and attributes"},{"paragraphs":["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."],"title":"Memory and temporary storage"},{"paragraphs":["The source callbacks below can coordinate execution or collect worker instrumentation. 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In any case, we'll use the index tuple not the heap tuple as the data source.","Note on Memory Ordering Effects: visibilitymap_get_status does not lock the visibility map buffer, and therefore the result we read here could be slightly stale. However, it can't be stale enough to matter."],"title":"Executor implementation notes"},{"code":"case T_IndexOnlyScan:\n\t\t\tpname = sname = \"Index Only Scan\";\n\t\t\tbreak;","title":"EXPLAIN identity in core source"}],"tables":[{"columns":[{"key":"label","label":"Text-format label"},{"key":"identity","label":"Structured node identity"}],"key":"explain-labels","rows":[{"identity":"Index Only Scan","label":"Index Only Scan"}],"title":"EXPLAIN labels in this source build"}]}},"RequestedLocale":"zh-Hans","Fallback":true,"Versions":["10","11","12","13","14","15","16","17","18","19","20"],"Locales":["en"],"Signatures":null,"Spellings":null,"SQLState":null,"Evidence":null}