data_directory

data_directory — Sets the server’s data directory. Observed in PG9.0–19 Beta 3; its last measured boot default is not set in PG19 Beta 3, with postmaster context. This is a beta-snapshot fact and can change before PostgreSQL 19 GA.

Note

Fact — official short description: “Sets the server’s data directory.”

Identity

Type , Valuestring: Upstream pg_settings type
Context , Valuepostmaster: Requires a server restart
Unit , Value—: Raw unit
Range , Value—: Raw limits in the last observed version
Enum values , Value—: — for non-enum types
Category , ValueFile Locations: Upstream classification
Latest boot value , Value—: not set

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	—	—	not set

How it works

Sets the server’s data directory. The value is fixed when the server starts, so changing it requires a restart.

This selects the cluster storage directory and overrides -D or PGDATA for data placement, but it does not relocate the already selected configuration files. Moving a cluster requires a coordinated shutdown and filesystem operation; changing only the string cannot move data.

Monitor and change data_directory together with allow_alter_system, config_file, hba_file. Validate on the relevant server role and real workload, then use its postmaster 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	data_directory is deployment topology, not workload tuning. Use an absolute path, least privilege, and atomic configuration rollout; verify access as the postgres service account before restart/reload.
OLAP	Follow the OLTP rule, and for separate mounts also verify boot ordering, backup coverage, and path consistency on failover nodes.
Small nodes	The default co-located layout is simplest. Split paths only for a concrete backup, packaging, or permission-isolation benefit.

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: PG9.0–19 Beta 3 unmodified; OLAP: PG9.0–19 Beta 3 unmodified; CRIT: PG9.0–19 Beta 3 unmodified; TINY: PG9.0–19 Beta 3 unmodified. No Pigsty-specific rationale is inferred from an absent override.

Common pitfalls

Missing directory traversal, read, or write permission for the service account.
Confusing restart requirements for a path with reload behavior of the selected file contents.
Omitting the path on a failover node or from backup inventory.
Using a relative path that depends on an unstable working directory.

allow_alter_system · config_file · hba_file · ident_file · external_pid_file · extension_destdir