{"Entry":{"collection":"guc","key":"autovacuum_vacuum_insert_scale_factor","name":"autovacuum_vacuum_insert_scale_factor","aliases":[],"metadata":{"baseline":false,"boot_human":"Not specified","boot_val":null,"category":"Vacuuming / Automatic Vacuuming","category_zh":"","changed_in":["18"],"changes":[{"documentation_changed":false,"fields":{},"from":"12","status":"added","to":"13"},{"documentation_changed":true,"fields":{"category":{"from":"Autovacuum","to":"Vacuuming / Automatic Vacuuming"}},"from":"17","status":"changed","to":"18"}],"content_hash":"5f501db9eda585c9f29918446bd0e7f8e5f092f4dc3433fad65c0d259c417e67","context":"","default_changed_in":[],"default_history":[{"from":"13","to":"19","value":"0.2"}],"derived_content_hash":"417939f487ca24cd0bc59fe9dec06b0135bf65b2d3e088975d9a0a90f66d271e","documentation_refresh":{"batch":"20261113","original_source_rev":"wiki-repair-20261023:c812894fd5a4fc1691311413d1423d7f2fb283f9cd12204d77068a1c88fe4c23","versions":{"14":"14.25","15":"15.20","16":"16.16","17":"17.12","18":"18.7","19":"19rc2"}},"editorial":{"advice":{"olap":"Run explicit ANALYZE/VACUUM after bulk loads instead of waiting only for proportional triggers; plan freezing and visibility-map advancement separately for append-only partitions.","oltp":"Tune autovacuum_vacuum_insert_scale_factor from table size, change rate, and maintenance SLA, using per-table thresholds for large/hot relations. Observe trigger intervals, dead tuples, and ANALYZE/VACUUM duration.","small":"Start with upstream. Fixed thresholds dominate on small tables; after changes, confirm worker and I/O headroom."},"mechanism":["Number of tuple inserts prior to vacuum as a fraction of reltuples. A configuration reload applies a new value; existing work already in flight is not retroactively changed.","For insert-heavy tables the trigger is the insert threshold plus insert scale factor times reltuples times the fraction not all-frozen. Such vacuuming can advance visibility/freeze state even without dead tuples and reduce later aggressive-vacuum work.","Monitor and change autovacuum_vacuum_insert_scale_factor together with autovacuum_vacuum_threshold, autovacuum_vacuum_scale_factor, autovacuum_vacuum_max_threshold. Validate on the relevant server role and real workload, then use its sighup context to choose session change, reload, or restart; a historical boot default is not the current effective value."],"pitfalls":["Changing the global value while a table storage parameter overrides it.","Treating reltuples and cumulative change statistics as exact real-time counts.","Blaming a threshold without checking long transactions, replication slots, and worker saturation.","Buying short-term quiet by deferring maintenance until wraparound failsafe activates."],"references":[{"title":"PostgreSQL 19 Beta 4: autovacuum_vacuum_insert_scale_factor","url":"https://www.postgresql.org/docs/19/runtime-config-vacuum.html#GUC-AUTOVACUUM-VACUUM-INSERT-SCALE-FACTOR"},{"title":"PostgreSQL 19 release notes","url":"https://www.postgresql.org/docs/19/release-19.html"}],"related":["autovacuum_vacuum_threshold","autovacuum_vacuum_scale_factor","autovacuum_vacuum_max_threshold","autovacuum_vacuum_insert_threshold","autovacuum","autovacuum_analyze_scale_factor"],"summary":"autovacuum_vacuum_insert_scale_factor sets the number of tuple inserts prior to vacuum as a fraction of reltuples. It is a sighup setting present in PG13–18; the latest recorded boot default is 0.2."},"enumvals":[],"first_version":"13","group":"Vacuuming","group_slug":"vacuum","imported_at":"2026-09-27T17:57:30.82832+08:00","intro_commit":{"authored_at":"2020-03-28T19:20:12+13:00","discussion":["https://postgr.es/m/CAC8Q8t%2Bj36G_bLF%3D%2B0iMo6jGNWnLnWb1tujXuJr-%2Bx8ZCCTqoQ%40mail.gmail.com"],"hash":"b07642dbcd8d5de05f0ee1dbb72dd6760dd30436","subject":"Trigger autovacuum based on number of INSERTs","url":"https://git.postgresql.org/gitweb/?p=postgresql.git;a=commit;h=b07642dbcd8d5de05f0ee1dbb72dd6760dd30436"},"key":"autovacuum_vacuum_insert_scale_factor","last_version":"20","max_val":"","min_val":"","name":"autovacuum_vacuum_insert_scale_factor","position":29,"present_in":["13","14","15","16","17","18","19","20"],"repair_provenance":{"original_source_revision":"english-manuals:b9582c34a80ada3406c09f08b6594bec28dadbaeaf319171cc242d18ca7d0a6b","receipt_sha256":"ec735bdbed5677e023fb6e923cee8946f9d9cca49655372906fdc9f1b0037666","repair":"wiki-repair-20261023"},"short_desc":"Specifies a fraction of the unfrozen pages in the table to add to autovacuum_vacuum_insert_threshold when deciding whether to trigger a VACUUM.","short_desc_zh":"","source_rev":"wiki-repair-20261023:c812894fd5a4fc1691311413d1423d7f2fb283f9cd12204d77068a1c88fe4c23","unit":"","vartype":"real"}},"Definition":{"Collection":"guc","Key":"autovacuum_vacuum_insert_scale_factor","SourceDatabase":"center","Version":"18","SourceTable":"guc","SourceKey":"autovacuum_vacuum_insert_scale_factor","SourceRevision":"wiki-repair-20261023:c812894fd5a4fc1691311413d1423d7f2fb283f9cd12204d77068a1c88fe4c23","Facts":{"boot_val":"0.2","category":"Vacuuming / Automatic Vacuuming","context":"sighup","description":"Specifies a fraction of the unfrozen pages in the table to add to autovacuum_vacuum_insert_threshold when deciding whether to trigger a VACUUM. 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