archive_command

archive_command — Sets the shell command that will be called to archive a WAL file. Observed in PG9.0–19 Beta 3; its last measured boot default is empty string 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 shell command that will be called to archive a WAL file.”

Identity

Type , Valuestring: Upstream pg_settings type
Context , Valuesighup: Takes effect after configuration reload
Unit , Value—: Raw unit
Range , Value—: Raw limits in the last observed version
Enum values , Value—: — for non-enum types
Category , ValueWrite-Ahead Log / Archiving: Upstream classification
Latest boot value , Value"": empty string

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	`""`	—	empty string

How it works

Sets the shell command that will be called to archive a WAL file. A configuration reload applies a new value; existing work already in flight is not retroactively changed.

The archiver expands %p to the source path and %f to the WAL file name, and considers exit status zero a durable success. A nonzero result is retried; a false success allows PostgreSQL to recycle the only local copy and silently breaks the archive chain.

Monitor and change archive_command together with archive_mode, archive_library, archive_timeout. 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	Manage archive_command as part of the backup/restore protocol: the command or module must be idempotent, fail visibly, and be verified by restoring from the real archive—not merely by exit status.
OLAP	Provision archive throughput and capacity for bulk-load WAL peaks. If archiving falls behind, throttle the job and alert; never hide backlog with false success or aggressive cleanup.
Small nodes	Enable it only for a defined PITR requirement and use a mature backup tool. Keep rebuildable instances simple, but never install a no-op command that creates the illusion of a backup.

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	`pgbackrest --stanza=fixture archive-push %p`	different	`'pgbackrest --stanza={{ pg_cluster }} archive-push %p'`
OLAP	`pgbackrest --stanza=fixture archive-push %p`	different	`'pgbackrest --stanza={{ pg_cluster }} archive-push %p'`
CRIT	`pgbackrest --stanza=fixture archive-push %p`	different	`'pgbackrest --stanza={{ pg_cluster }} archive-push %p'`
TINY	`pgbackrest --stanza=fixture archive-push %p`	different	`'pgbackrest --stanza={{ pg_cluster }} archive-push %p'`

Caution

Advice — pending human review. Fact from the current Pigsty template projection: OLTP: PG9.0–19 Beta 3 = pgbackrest –stanza=fixture archive-push %p (dcs); OLAP: PG9.0–19 Beta 3 = pgbackrest –stanza=fixture archive-push %p (dcs); CRIT: PG9.0–19 Beta 3 = pgbackrest –stanza=fixture archive-push %p (dcs); TINY: PG9.0–19 Beta 3 = pgbackrest –stanza=fixture archive-push %p (dcs). Advice, pending human review — Editorial interpretation, pending human maintainer review: the override appears intended to bind archiving to the pgBackRest stanza used by Pigsty for PITR; confirm it against the current Pigsty templates, hardware fixture, and operational guarantees before publication.

Common pitfalls

Returning success before the archive copy is durable or verified.
Failing to quote %p/%f safely in a shell command.
Letting repeated failures fill pg_wal and stop the server.
Confusing pg_settings base units with human-readable configuration units.
Benchmarking throughput without a crash-recovery and archive-restore test.

archive_mode · archive_library · archive_timeout · archive_cleanup_command · restore_command · recovery_end_command