idle_in_transaction_session_timeout

idle_in_transaction_session_timeout is the PostgreSQL setting that defines the maximum allowed idle time between queries, when in a transaction.

Note

Fact — official short description: “Sets the maximum allowed idle time between queries, when in a transaction.”

Identity

Type , Valueinteger: Upstream pg_settings type
Context , Valueuser: Settable by an ordinary user
Unit , Valuems: Raw unit
Range , Value0 – 2147483647: 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 , Value0: 0 ms

Lifecycle

Fact	Value
First observed	PG9.6
Present in	PG9.6–19 Beta 3
Removed in	No
Introduction commit	`c6dda1f48e57` — Add idle_in_transaction_session_timeout.
Commit date	2016-03-16
Discussion	—

Default history

Measured PG9.0–19 Beta 3 boot defaults
Versions	Raw `boot_val`	Unit	Human value
PG9.6–19 Beta 3	`0`	`ms`	0 ms

How it works

idle_in_transaction_session_timeout sets the maximum allowed idle time between queries, when in a transaction. 0 disables the timeout. It terminates sessions idle inside an open transaction, releasing locks and old snapshots that can block vacuum cleanup and cause bloat.

idle_in_transaction_session_timeout 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.

Timeouts overlap: the first applicable deadline wins, while client, pooler, TCP, and server cancellation behavior determines whether work is retried, canceled, or the session is closed.

Tuning advice

Tip

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

Workload	Guidance
OLTP	Set idle_in_transaction_session_timeout from the service latency and failure budget, preferably per role or application. Test retries and cancellation paths before enforcing a cluster-wide value.
OLAP	Analytical work usually needs a larger or job-specific idle_in_transaction_session_timeout; preserve a finite guardrail for abandoned work without killing legitimate long scans.
Small nodes	Use a conservative finite idle_in_transaction_session_timeout only when the client or operating system handles termination correctly; verify that maintenance still has a dedicated exception.

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	`10min`	different	`10min`
OLAP	`0`	same as boot	`0`
CRIT	`1min`	different	`1min`
TINY	`10min`	different	`10min`

Caution

Advice — pending human review. Fact from the current Pigsty template projection: OLTP: PG9.6–19 Beta 3 = 10min (dcs); OLAP: PG9.6–19 Beta 3 = 0 (dcs); CRIT: PG9.6–19 Beta 3 = 1min (dcs); TINY: PG9.6–19 Beta 3 = 10min (dcs). Advice, pending human review — Editorial inference: The templates bound abandoned open transactions, use a stricter limit for CRIT, and leave OLAP unlimited for deliberately long analytical transactions; each workload still needs pooler and retry review.

Common pitfalls

Changing idle_in_transaction_session_timeout in one session and assuming role defaults, database defaults, or other pooled sessions changed with it.
Forgetting that zero usually disables the timeout or delegates behavior to the operating system.
Setting overlapping deadlines without deciding which layer owns retries, cancellation, and connection disposal.
Changing idle_in_transaction_session_timeout globally without a rollback plan and a client or operational compatibility test.

statement_timeout · lock_timeout · transaction_timeout · idle_session_timeout · deadlock_timeout