autovacuum_vacuum_max_threshold

autovacuum_vacuum_max_threshold — Maximum number of tuple updates or deletes prior to vacuum. Observed in PG18–19 Beta 3; its last measured boot default is 100000000 in PG19 Beta 3, with sighup context. This is a beta-snapshot fact and can change before PostgreSQL 19 GA.

Note

Fact — official short description: “Maximum number of tuple updates or deletes prior to vacuum.”

Identity

Type , Valueinteger: Upstream pg_settings type
Context , Valuesighup: Takes effect after configuration reload
Unit , Value—: Raw unit
Range , Value-1 – 2147483647: Raw limits in the last observed version
Enum values , Value—: — for non-enum types
Category , ValueVacuuming / Automatic Vacuuming: Upstream classification
Latest boot value , Value100000000: 100000000

Lifecycle

Fact	Value
First observed	PG18
Present in	PG18–19 Beta 3
Removed in	No
Introduction commit	`306dc520b9df` — Introduce autovacuum_vacuum_max_threshold.
Commit date	2025-02-05
Discussion	thread 1

Default history

Measured PG9.0–19 Beta 3 boot defaults
Versions	Raw `boot_val`	Unit	Human value
PG18–19 Beta 3	`100000000`	—	100000000

How it works

Maximum number of tuple updates or deletes prior to vacuum. A configuration reload applies a new value; existing work already in flight is not retroactively changed.

The ordinary automatic-vacuum threshold is the base term plus scale factor times reltuples, capped by autovacuum_vacuum_max_threshold from PG18. It reacts to dead tuples from updates/deletes, permits per-table overrides, and is separate from mandatory anti-wraparound vacuuming.

Monitor and change autovacuum_vacuum_max_threshold together with autovacuum_vacuum_threshold, autovacuum_vacuum_scale_factor, autovacuum_vacuum_insert_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.

Tuning advice

Tip

Advice. These are workload-specific starting points and must be validated with measurements.

Workload	Guidance
OLTP	Tune autovacuum_vacuum_max_threshold 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.
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.
Small nodes	Start with upstream or the measured Pigsty matrix value. Fixed thresholds dominate on small tables; after changes, confirm worker and I/O headroom.

Pigsty

Values use the fixed 8-vCPU, 32-GiB, 100-GiB SSD fixture and render the current Pigsty templates for PG19 Beta 3; this does not assert current Pigsty support for that historical or beta release.

Template	Effective value	Versus upstream boot	Source expression
OLTP	Unmodified	—	—
OLAP	Unmodified	—	—
CRIT	Unmodified	—	—
TINY	Unmodified	—	—

Caution

Advice — pending human review. Fact from the current Pigsty template projection: OLTP: PG18–19 Beta 3 unmodified; OLAP: PG18–19 Beta 3 unmodified; CRIT: PG18–19 Beta 3 unmodified; TINY: PG18–19 Beta 3 unmodified. No Pigsty-specific rationale is inferred from an absent override.

Common 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.

autovacuum_vacuum_threshold · autovacuum_vacuum_scale_factor · autovacuum_vacuum_insert_threshold · autovacuum_vacuum_insert_scale_factor · autovacuum · autovacuum_analyze_scale_factor