{"Entry":{"collection":"relopts","key":"toast-autovacuum-multixact-freeze-max-age","name":"toast.autovacuum_multixact_freeze_max_age","aliases":["autovacuum_multixact_freeze_max_age"],"metadata":{"aliases":["autovacuum_multixact_freeze_max_age"],"category":"TOAST tables","content_hash":"fe1f0f01a85b27cceeb0f4ba8773ec12e5529fb711084fc0799b32523e5f6384","derived_content_hash":"4a90e7955f64854b8dbfcc01233f9e67eedbdefaf790dcfeea36f0c42932a914","imported_at":"2026-09-30T17:44:22.315689+08:00","name":"toast.autovacuum_multixact_freeze_max_age","name_zh":"TOAST autovacuum_multixact_freeze_max_age","repair_provenance":{"original_source_revision":"","receipt_sha256":"7d4f81e5659f098811eedafec64bd891a4aec033d4558dbf086f95699393015b","repair":"wiki-repair-20261023"},"slug":"toast-autovacuum-multixact-freeze-max-age","source_rev":"wiki-repair-20261023:49e17dcb01239a8d84911efe0c7edb714c233456cba4bba568403f3a551e48f6","summary":"Per-table value for autovacuum_multixact_freeze_max_age parameter. Note that autovacuum will ignore per-table autovacuum_multixact_freeze_max_age parameters that are larger than the system-wide setting (it can only be set smaller)."}},"Definition":{"Collection":"relopts","Key":"toast-autovacuum-multixact-freeze-max-age","SourceDatabase":"center","Version":"18","SourceTable":"relopt","SourceKey":"toast-autovacuum-multixact-freeze-max-age","SourceRevision":"eb6c2292fdf28e1b4635ab478eec3919411cdf4a6c07553387870e26201f3744","Facts":{"description":["Per-table value for autovacuum_multixact_freeze_max_age parameter. Note that autovacuum will ignore per-table autovacuum_multixact_freeze_max_age parameters that are larger than the system-wide setting (it can only be set smaller)."],"description_zh":"autovacuum_multixact_freeze_max_age 参数的每表取值。注意，自动清理会忽略大于系统范围设置的每表 autovacuum_multixact_freeze_max_age 参数（它只能设置得更小）。","description_zh_html":"\u003cp\u003e\n\u003ca class=\"xref\" href=\"/zh/docs/18/runtime-config-vacuum.html#GUC-AUTOVACUUM-MULTIXACT-FREEZE-MAX-AGE\"\u003eautovacuum_multixact_freeze_max_age\u003c/a\u003e 参数的每表取值。注意，自动清理会忽略大于系统范围设置的每表\n      \u003ccode class=\"literal\"\u003eautovacuum_multixact_freeze_max_age\u003c/code\u003e 参数（它只能设置得更小）。\n     \u003c/p\u003e\u003ch3\u003e相关全局参数\u003c/h3\u003e\u003cp\u003e\n        指定在必须强制执行 \u003ccode class=\"command\"\u003eVACUUM\u003c/code\u003e 以防止表内多事务 ID 回卷之前，一个表的 \u003ccode class=\"structname\"\u003epg_class\u003c/code\u003e.\u003ccode class=\"structfield\"\u003erelminmxid\u003c/code\u003e\n        字段可以达到的最大年龄（以多事务计）。注意即使自动清理被禁用，系统也会启动自动清理进程来防止回卷。\n       \u003c/p\u003e\u003cp\u003e\n        清理多事务也允许从 \u003ccode class=\"filename\"\u003epg_multixact/members\u003c/code\u003e 和 \u003ccode class=\"filename\"\u003epg_multixact/offsets\u003c/code\u003e 子目录中移除旧文件，这也是为什么默认值被设置为较低的 4 亿个多事务。该参数只能在服务器启动时设置，但是对于个别表可以通过修改表存储参数来降低该设置。详见\u003ca class=\"xref\" href=\"/zh/docs/18/routine-vacuuming.html#VACUUM-FOR-MULTIXACT-WRAPAROUND\" title=\"24.1.5.1. 多事务与回卷\"\u003e第 24.1.5.1 节\u003c/a\u003e。\n       \u003c/p\u003e","facts":[{"label":"Applies to","value":"TOAST tables"},{"label":"Value type","value":"integer"}],"related":[{"label":"Table option autovacuum_multixact_freeze_max_age","url":"/wiki/relopts/table-autovacuum-multixact-freeze-max-age/?v=18"},{"label":"Global parameter autovacuum_multixact_freeze_max_age","url":"/wiki/guc/autovacuum_multixact_freeze_max_age/?v=18"},{"label":"CREATE TABLE","url":"/wiki/sql/create-table/?v=18"}],"release":{"channel":"stable","label":"18.6","major":"18","ref":"Local English manual 18.6","revision":"eb6c2292fdf28e1b4635ab478eec3919411cdf4a6c07553387870e26201f3744"},"sections":[{"paragraphs":["This option applies to the associated TOAST table. Set it with the toast. prefix in WITH or ALTER TABLE SET. An unset TOAST option inherits the corresponding explicitly set parent-table option.","The manual describes table and TOAST forms together. Autoanalyze does not apply to TOAST tables; only explicitly documented toast. forms are listed here."],"title":"TOAST inheritance"},{"paragraphs":["The WITH clause can specify storage parameters for tables, and for indexes associated with a UNIQUE , PRIMARY KEY , or EXCLUDE constraint. Storage parameters for indexes are documented in CREATE INDEX . The storage parameters currently available for tables are listed below. For many of these parameters, as shown, there is an additional parameter with the same name prefixed with toast. , which controls the behavior of the table's secondary TOAST table, if any (see Section 66.2 for more information about TOAST). If a table parameter value is set and the equivalent toast. parameter is not, the TOAST table will use the table's parameter value. Specifying these parameters for partitioned tables is not supported, but you may specify them for individual leaf partitions."],"title":"Common table storage rules"},{"paragraphs":["This clause specifies optional storage parameters for the new materialized view; see Storage Parameters in the CREATE TABLE documentation for more information. All parameters supported for CREATE TABLE are also supported for CREATE MATERIALIZED VIEW . See CREATE TABLE for more information."],"title":"Materialized views"},{"paragraphs":["The following same-version GUC definition explains its purpose and units. Global defaults and activation rules describe the GUC; the relation-option override rules remain those above.","Specifies the maximum age (in multixacts) that a table's pg_class . relminmxid field can attain before a VACUUM operation is forced to prevent multixact ID wraparound within the table. Note that the system will launch autovacuum processes to prevent wraparound even when autovacuum is otherwise disabled.","Vacuuming multixacts also allows removal of old files from the pg_multixact/members and pg_multixact/offsets subdirectories, which is why the default is a relatively low 400 million multixacts. This parameter can only be set at server start, but the setting can be reduced for individual tables by changing table storage parameters. For more information see Section 24.1.5.1 ."],"title":"Related global parameter: autovacuum_multixact_freeze_max_age"}],"signature":"WITH (toast.autovacuum_multixact_freeze_max_age = value)","sources":[{"label":"PostgreSQL 18 English manual","path":"sql-createtable.html","sha256":"b4d703391fe1102d0e02bd6769bef928513eb7a5542f38f7448fc77fe69e0d5b","url":"/docs/18/sql-createtable.html#RELOPTION-AUTOVACUUM-MULTIXACT-FREEZE-MAX-AGE"},{"label":"Related global parameter: autovacuum_multixact_freeze_max_age","path":"runtime-config-vacuum.html","sha256":"7047f1fa9138b97f1812532f8a905fa7479451dfd64655e029a7d387b20b22e4","url":"/docs/18/runtime-config-vacuum.html#GUC-AUTOVACUUM-MULTIXACT-FREEZE-MAX-AGE"},{"label":"PostgreSQL 18 English manual","path":"sql-creatematerializedview.html","sha256":"bd8a6710c9f133afee191eb0ec345ef8c54bb54db2242621d8cb683c783a8b18","url":"/docs/18/sql-creatematerializedview.html"}],"translation_provenance":{"inputs":[{"kind":"current-pgdoc-translation","path":"/Users/vonng/pgsty/pgdoc/zh/18/html/sql-createtable.html","sha256":"c044586c69b191e0f39966b25811a0c70f12fe2bf5e7f640501e53d76ca8f775"},{"kind":"current-pgdoc-translation","path":"/Users/vonng/pgsty/pgdoc/zh/18/html/runtime-config-vacuum.html","sha256":"ea621aa6ed500fc56d21868a21fd313872cec24b86caf4c8f9bdfdc804b8235f"}],"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-createtable.html","sha256":"b4d703391fe1102d0e02bd6769bef928513eb7a5542f38f7448fc77fe69e0d5b","url":"/docs/18/sql-createtable.html#RELOPTION-AUTOVACUUM-MULTIXACT-FREEZE-MAX-AGE"},{"label":"Related global parameter: autovacuum_multixact_freeze_max_age","path":"runtime-config-vacuum.html","sha256":"7047f1fa9138b97f1812532f8a905fa7479451dfd64655e029a7d387b20b22e4","url":"/docs/18/runtime-config-vacuum.html#GUC-AUTOVACUUM-MULTIXACT-FREEZE-MAX-AGE"},{"label":"PostgreSQL 18 English manual","path":"sql-creatematerializedview.html","sha256":"bd8a6710c9f133afee191eb0ec345ef8c54bb54db2242621d8cb683c783a8b18","url":"/docs/18/sql-creatematerializedview.html"}]},"MeasuredEvidence":{}},"Text":{"Collection":"relopts","Key":"toast-autovacuum-multixact-freeze-max-age","SourceDatabase":"center","Version":"18","Locale":"en","Title":"toast.autovacuum_multixact_freeze_max_age","Summary":"Per-table value for autovacuum_multixact_freeze_max_age parameter. Note that autovacuum will ignore per-table autovacuum_multixact_freeze_max_age parameters that are larger than the system-wide setting (it can only be set smaller).","BodyHTML":"\u003cp\u003ePer-table value for autovacuum_multixact_freeze_max_age parameter. Note that autovacuum will ignore per-table autovacuum_multixact_freeze_max_age parameters that are larger than the system-wide setting (it can only be set smaller).\u003c/p\u003e","SourceRevision":"eb6c2292fdf28e1b4635ab478eec3919411cdf4a6c07553387870e26201f3744","ContentHash":"c7489fe280ad506629b1278e7fc1b2bceab10d3952aa3a0d05895a286d37d791","Payload":{"description":["Per-table value for autovacuum_multixact_freeze_max_age parameter. Note that autovacuum will ignore per-table autovacuum_multixact_freeze_max_age parameters that are larger than the system-wide setting (it can only be set smaller)."],"related":[{"label":"Table option autovacuum_multixact_freeze_max_age","url":"/wiki/relopts/table-autovacuum-multixact-freeze-max-age/?v=18"},{"label":"Global parameter autovacuum_multixact_freeze_max_age","url":"/wiki/guc/autovacuum_multixact_freeze_max_age/?v=18"},{"label":"CREATE TABLE","url":"/wiki/sql/create-table/?v=18"}],"sections":[{"paragraphs":["This option applies to the associated TOAST table. Set it with the toast. prefix in WITH or ALTER TABLE SET. An unset TOAST option inherits the corresponding explicitly set parent-table option.","The manual describes table and TOAST forms together. Autoanalyze does not apply to TOAST tables; only explicitly documented toast. forms are listed here."],"title":"TOAST inheritance"},{"paragraphs":["The WITH clause can specify storage parameters for tables, and for indexes associated with a UNIQUE , PRIMARY KEY , or EXCLUDE constraint. Storage parameters for indexes are documented in CREATE INDEX . The storage parameters currently available for tables are listed below. For many of these parameters, as shown, there is an additional parameter with the same name prefixed with toast. , which controls the behavior of the table's secondary TOAST table, if any (see Section 66.2 for more information about TOAST). If a table parameter value is set and the equivalent toast. parameter is not, the TOAST table will use the table's parameter value. Specifying these parameters for partitioned tables is not supported, but you may specify them for individual leaf partitions."],"title":"Common table storage rules"},{"paragraphs":["This clause specifies optional storage parameters for the new materialized view; see Storage Parameters in the CREATE TABLE documentation for more information. All parameters supported for CREATE TABLE are also supported for CREATE MATERIALIZED VIEW . See CREATE TABLE for more information."],"title":"Materialized views"},{"paragraphs":["The following same-version GUC definition explains its purpose and units. Global defaults and activation rules describe the GUC; the relation-option override rules remain those above.","Specifies the maximum age (in multixacts) that a table's pg_class . relminmxid field can attain before a VACUUM operation is forced to prevent multixact ID wraparound within the table. Note that the system will launch autovacuum processes to prevent wraparound even when autovacuum is otherwise disabled.","Vacuuming multixacts also allows removal of old files from the pg_multixact/members and pg_multixact/offsets subdirectories, which is why the default is a relatively low 400 million multixacts. This parameter can only be set at server start, but the setting can be reduced for individual tables by changing table storage parameters. For more information see Section 24.1.5.1 ."],"title":"Related global parameter: autovacuum_multixact_freeze_max_age"}]}},"RequestedLocale":"en","Fallback":false,"Versions":["10","11","12","13","14","15","16","17","18","19","20"],"Locales":["en","zh-Hans"],"Signatures":null,"Spellings":null,"SQLState":null,"Evidence":null}