checkpoint_timeout

checkpoint_timeout — Sets the maximum time between automatic WAL checkpoints. Observed in PG9.0–19 Beta 3; its last measured boot default is 5 min 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: “Sets the maximum time between automatic WAL checkpoints.”

Identity

Type , Valueinteger: Upstream pg_settings type
Context , Valuesighup: Takes effect after configuration reload
Unit , Values: Raw unit
Range , Value30 – 86400: Raw limits in the last observed version
Enum values , Value—: — for non-enum types
Category , ValueWrite-Ahead Log / Checkpoints: Upstream classification
Latest boot value , Value300: 5 min

Lifecycle

Fact	Value
First observed	PG9.0 (research boundary)
Present in	PG9.0–19 Beta 3
Removed in	No
Introduction commit	Not asserted: predates the PG9.0 research boundary
Commit date	—
Discussion	—

Default history

Measured PG9.0–19 Beta 3 boot defaults
Versions	Raw `boot_val`	Unit	Human value
PG9.0–19 Beta 3	`300`	`s`	5 min

How it works

An automatic checkpoint is considered after checkpoint_timeout, but max_wal_size can force one earlier. If no WAL has been written since the preceding checkpoint, PostgreSQL can skip the timed checkpoint, so this setting is a maximum scheduling interval rather than a promise of periodic physical work.

Longer intervals usually reduce checkpoint frequency and full-page-write amplification, while increasing the amount of WAL that crash recovery may need to replay. Shorter intervals bound that replay horizon more tightly but increase dirty-page flushing and post-checkpoint full-page images.

Checkpoint records also constrain restartpoints on standbys. This parameter should not be used to set a WAL-archive recovery point objective; archive_timeout is the control intended to force segment switches for low-WAL systems.

Tuning advice

Tip

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

Workload	Guidance
OLTP	Tune it together with max_wal_size and keep checkpoint I/O spread with checkpoint_completion_target. Extend the interval only after measuring recovery requirements, requested versus timed checkpoints, write latency, and WAL volume.
OLAP	During bulk work, max_wal_size often triggers before the timer. Increase WAL capacity first if volume-driven checkpoints dominate, and retain a timeout that still meets restart and recovery expectations.
Small nodes	The upstream 5-minute default is a defensible starting point where recovery time matters and storage is limited. A longer interval needs explicit disk headroom and a tested crash-recovery budget.

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	`15min`	different	`15min`
OLAP	`15min`	different	`15min`
CRIT	`15min`	different	`15min`
TINY	`15min`	different	`15min`

Caution

Advice — pending human review. Fact from the current Pigsty template projection: OLTP: PG9.0–19 Beta 3 = 15min (dcs); OLAP: PG9.0–19 Beta 3 = 15min (dcs); CRIT: PG9.0–19 Beta 3 = 15min (dcs); TINY: PG9.0–19 Beta 3 = 15min (dcs). Advice, pending human review — confirm the operational intent against the current Pigsty templates and supported PostgreSQL versions before publication.

Common pitfalls

Assuming a checkpoint occurs exactly every configured interval even on an idle system.
Forgetting that max_wal_size can trigger a checkpoint earlier.
Using checkpoint_timeout instead of archive_timeout to bound archive delay.
Increasing it without allowing for a longer crash-recovery replay horizon.
Reducing it so far that full-page writes and checkpoint I/O dominate.

max_wal_size · checkpoint_completion_target · checkpoint_warning · archive_timeout · full_page_writes · checkpoint_flush_after