temp_tablespaces

temp_tablespaces is the PostgreSQL setting that defines the tablespace(s) to use for temporary tables and sort files.

Note

Fact — official short description: “Sets the tablespace(s) to use for temporary tables and sort files.”

Identity

Type , Valuestring: Upstream pg_settings type
Context , Valueuser: Settable by an ordinary user
Unit , Value—: Raw unit
Range , Value—: Raw limits in the last observed version
Enum values , Value—: — for non-enum types
Category , ValueClient Connection Defaults / Statement Behavior: 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

temp_tablespaces sets the tablespace(s) to use for temporary tables and sort files. An empty string means use the database’s default tablespace. PostgreSQL uses the list for temporary relations and executor spill files, choosing among multiple entries to distribute work; permissions and existence are checked by context.

temp_tablespaces 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.

It supplies a default only when SQL omits an explicit choice, so schema migrations, object-level options, privileges, and later ALTER operations can override or outlive it.

Tuning advice

Tip

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

Workload	Guidance
OLTP	Keep temp_tablespaces aligned with schema-management policy and make important storage choices explicit in migrations. Benchmark any physical-layout change with production-shaped writes.
OLAP	Use temp_tablespaces deliberately for bulk objects and spill-heavy jobs, checking I/O placement, compression support, and operational tooling before adoption.
Small nodes	Prefer the upstream default for temp_tablespaces unless the node has a verified alternate storage path or restore requirement; simplicity reduces recovery surprises.

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

Changing temp_tablespaces in one session and assuming role defaults, database defaults, or other pooled sessions changed with it.
Expecting a changed default to rewrite existing objects or override explicit DDL clauses.
Ignoring tablespace privileges, installed access methods or compression support, and restore portability.
Changing temp_tablespaces globally without a rollback plan and a client or operational compatibility test.

default_table_access_method · default_tablespace · default_toast_compression · check_function_bodies · maintenance_work_mem