{"Entry":{"collection":"relopts","key":"btree-deduplicate-items","name":"deduplicate_items","aliases":["btree.deduplicate_items"],"metadata":{"aliases":["btree.deduplicate_items"],"category":"B-tree indexes","content_hash":"609d50785f79e19cc923b444ea4cd0ea130253ba592fe34c60ef49a29237c5b3","derived_content_hash":"8ea1c628b76dc5d7a9dcda7522cb88c53de2ff7302fc0515f1519d59a5a2c433","imported_at":"2026-09-30T17:44:22.129848+08:00","name":"deduplicate_items","name_zh":"deduplicate_items","repair_provenance":{"original_source_revision":"","receipt_sha256":"527d1b8f4bf52fbca04285879f891e37318fe85e66a93e8b308c0e74a7b2b5af","repair":"wiki-repair-20261023"},"slug":"btree-deduplicate-items","source_rev":"wiki-repair-20261023:35db6edba608711a43024f0211ca7cb93e3702bdeb31400a6436bd7c2e2c409e","summary":"Controls usage of the B-tree deduplication technique described in Section 65.1.4.3 . Set to ON or OFF to enable or disable the optimization. (Alternative spellings of ON and OFF are allowed as described in Section 19.1 .) The default is ON ."}},"Definition":{"Collection":"relopts","Key":"btree-deduplicate-items","SourceDatabase":"center","Version":"18","SourceTable":"relopt","SourceKey":"btree-deduplicate-items","SourceRevision":"eb6c2292fdf28e1b4635ab478eec3919411cdf4a6c07553387870e26201f3744","Facts":{"description":["Controls usage of the B-tree deduplication technique described in Section 65.1.4.3 . Set to ON or OFF to enable or disable the optimization. (Alternative spellings of ON and OFF are allowed as described in Section 19.1 .) The default is ON .","Turning deduplicate_items off via ALTER INDEX prevents future insertions from triggering deduplication, but does not in itself make existing posting list tuples use the standard tuple representation."],"description_zh":"控制是否使用第 65.1.4.3 节中描述的 B-树去重技术。设置为 ON 或 OFF 可启用或禁用该优化。（ON 和 OFF 的其他拼写形式也被接受，如第 19.1 节所述。）默认值为 ON。 注意 通过 ALTER INDEX 关闭 deduplicate_items 可以防止将来的插入触发去重，但这本身不会让现有倒排列表元组改用标准的元组表示。","description_zh_html":"\u003cp\u003e\n      控制是否使用\u003ca class=\"xref\" href=\"/zh/docs/18/btree.html#BTREE-DEDUPLICATION\" title=\"65.1.4.3. 去重\"\u003e第 65.1.4.3 节\u003c/a\u003e中描述的 B-树去重技术。设置为 \u003ccode class=\"literal\"\u003eON\u003c/code\u003e 或 \u003ccode class=\"literal\"\u003eOFF\u003c/code\u003e 可启用或禁用该优化。（\u003ccode class=\"literal\"\u003eON\u003c/code\u003e 和 \u003ccode class=\"literal\"\u003eOFF\u003c/code\u003e 的其他拼写形式也被接受，如\u003ca class=\"xref\" href=\"/zh/docs/18/config-setting.html\" title=\"19.1. 设置参数\"\u003e第 19.1 节\u003c/a\u003e所述。）默认值为 \u003ccode class=\"literal\"\u003eON\u003c/code\u003e。\n    \u003c/p\u003e\u003cdiv class=\"note\"\u003e\u003ch3 class=\"title\"\u003e注意\u003c/h3\u003e\u003cp\u003e\n      通过 \u003ccode class=\"command\"\u003eALTER INDEX\u003c/code\u003e 关闭 \u003ccode class=\"literal\"\u003ededuplicate_items\u003c/code\u003e\n      可以防止将来的插入触发去重，但这本身不会让现有倒排列表元组改用标准的元组表示。\n     \u003c/p\u003e\u003c/div\u003e","facts":[{"label":"Applies to","value":"B-tree indexes"},{"label":"Value type","value":"boolean"},{"label":"Default","value":"ON"}],"related":[{"label":"CREATE INDEX","url":"/wiki/sql/create-index/?v=18"}],"release":{"channel":"stable","label":"18.6","major":"18","ref":"Local English manual 18.6","revision":"eb6c2292fdf28e1b4635ab478eec3919411cdf4a6c07553387870e26201f3744"},"sections":[{"paragraphs":["This entry applies to B-tree indexes. Set it with CREATE INDEX WITH or ALTER INDEX SET. Read defaults and behavior for this specific access method."],"title":"Index access method"}],"signature":"WITH (deduplicate_items = value)","sources":[{"label":"PostgreSQL 18 English manual","path":"sql-createindex.html","sha256":"6aa00da55815d13d0355dd25cb1cdb603fa36964993f164d1b6f486011282580","url":"/docs/18/sql-createindex.html#INDEX-RELOPTION-DEDUPLICATE-ITEMS"}],"translation_provenance":{"inputs":[{"kind":"current-pgdoc-translation","path":"/Users/vonng/pgsty/pgdoc/zh/18/html/sql-createindex.html","sha256":"ce2d5ba3eb6a7da215b754fefccac3a37794c6ec20de7eac0bf4f97034328d82"}],"kind":"same-version-pgdoc","locale":"zh-Hans","source_revision":"b1b500221dbe5437cfca004d6b04d3f6e422765d","version":"18"},"zh_from":"same-version-pgdoc"},"ManualEvidence":{"release":{"channel":"stable","label":"18.6","major":"18","ref":"Local English manual 18.6","revision":"eb6c2292fdf28e1b4635ab478eec3919411cdf4a6c07553387870e26201f3744"},"sources":[{"label":"PostgreSQL 18 English manual","path":"sql-createindex.html","sha256":"6aa00da55815d13d0355dd25cb1cdb603fa36964993f164d1b6f486011282580","url":"/docs/18/sql-createindex.html#INDEX-RELOPTION-DEDUPLICATE-ITEMS"}]},"MeasuredEvidence":{}},"Text":{"Collection":"relopts","Key":"btree-deduplicate-items","SourceDatabase":"center","Version":"18","Locale":"en","Title":"deduplicate_items","Summary":"Controls usage of the B-tree deduplication technique described in Section 65.1.4.3 . Set to ON or OFF to enable or disable the optimization. (Alternative spellings of ON and OFF are allowed as described in Section 19.1 .) The default is ON .\nTurning deduplicate_items off via ALTER INDEX prevents future insertions from triggering deduplication, but does not in itself make existing posting list tuples use the standard tuple representation.","BodyHTML":"\u003cp\u003eControls usage of the B-tree deduplication technique described in Section 65.1.4.3 . Set to ON or OFF to enable or disable the optimization. (Alternative spellings of ON and OFF are allowed as described in Section 19.1 .) The default is ON .\nTurning deduplicate_items off via ALTER INDEX prevents future insertions from triggering deduplication, but does not in itself make existing posting list tuples use the standard tuple representation.\u003c/p\u003e","SourceRevision":"eb6c2292fdf28e1b4635ab478eec3919411cdf4a6c07553387870e26201f3744","ContentHash":"20e22a121e769f4cbb52609b71f000acd4831d8f30db0fba571cc8b0c1df4547","Payload":{"description":["Controls usage of the B-tree deduplication technique described in Section 65.1.4.3 . Set to ON or OFF to enable or disable the optimization. (Alternative spellings of ON and OFF are allowed as described in Section 19.1 .) The default is ON .","Turning deduplicate_items off via ALTER INDEX prevents future insertions from triggering deduplication, but does not in itself make existing posting list tuples use the standard tuple representation."],"related":[{"label":"CREATE INDEX","url":"/wiki/sql/create-index/?v=18"}],"sections":[{"paragraphs":["This entry applies to B-tree indexes. Set it with CREATE INDEX WITH or ALTER INDEX SET. Read defaults and behavior for this specific access method."],"title":"Index access method"}]}},"RequestedLocale":"en","Fallback":false,"Versions":["13","14","15","16","17","18","19","20"],"Locales":["en","zh-Hans"],"Signatures":null,"Spellings":null,"SQLState":null,"Evidence":null}