vacuum_cleanup_index_scale_factor

Definition PG 13 manual

No dedicated definition was found in this manual. The parameter’s presence and values come from the metadata snapshot identified above.

How it works

vacuum_cleanup_index_scale_factor sets the number of tuple inserts prior to index cleanup as a fraction of reltuples. The PostgreSQL 11–13 knob delayed index cleanup after inserts; it was removed in PostgreSQL 14 when the index-cleanup decision model changed.

vacuum_cleanup_index_scale_factor is a USER-context setting. An authorized role can change it for a session, while ALTER ROLE or ALTER DATABASE can establish a default for future sessions.

The legacy decision applied to B-tree cleanup scans and interacted with VACUUM statistics, inserted tuples, reusable index pages, and autovacuum scheduling; it was not a GIN control.

Operational considerations

Changing vacuum_cleanup_index_scale_factor in one session and assuming role defaults, database defaults, or other pooled sessions changed with it.

Applying an old B-tree cleanup heuristic without measuring index scans, reusable pages, and VACUUM behavior on the exact release.

Confusing a removed session default with current autovacuum thresholds or per-table storage parameters.

Keeping an unknown-parameter line during a PostgreSQL 14+ upgrade.

Workload guidance

OLAP: For legacy bulk-load systems, measure actual index maintenance rather than carrying this removed knob forward as configuration folklore.

OLTP: Do not tune vacuum_cleanup_index_scale_factor for a current server: PostgreSQL removed it in 14. On PostgreSQL 11–13, change it only for a measured index-cleanup problem and plan the upgrade behavior.

SMALL: Leave the legacy default and upgrade; a removed parameter is not a durable way to manage small-node vacuum cost.