# lock_timeout

> lock_timeout is the PostgreSQL setting that defines the maximum allowed duration of any wait for a lock.
---

> [!NOTE]
> **Fact — official short description:** “Sets the maximum allowed duration of any wait for a lock.”

## Identity {#identity}

| Field | Value | Meaning |
| --- | --- | --- |
| Type | `integer` | Upstream pg_settings type |
| Context | `user` | Settable by an ordinary user |
| Unit | `ms` | Raw unit |
| Range | `0` – `2147483647` | Raw limits in the last observed version |
| Enum values | — | — for non-enum types |
| Category | Client Connection Defaults / Statement Behavior | Upstream classification |
| Latest boot value | `0` | 0 ms |
{.fields meta="-"}

## Lifecycle {#lifecycle}

| Fact | Value |
| --- | --- |
| First observed | PG9.3 |
| Present in | PG9.3–19 Beta 3 |
| Removed in | No |
| Introduction commit | [`d43837d03067`](https://git.postgresql.org/gitweb/?p=postgresql.git;a=commit;h=d43837d03067487560af481474ae985df894f786) — Add lock_timeout configuration parameter. |
| Commit date | 2013-03-16 |
| Discussion | — |

## Default history {#default-history}

| Versions | Raw `boot_val` | Unit | Human value |
| --- | --- | --- | --- |
| PG9.3–19 Beta 3 | `0` | `ms` | 0 ms |
{.full-width caption="Measured PG9.0–19 Beta 3 boot defaults"}

## How it works {#mechanism}

lock_timeout sets the maximum allowed duration of any wait for a lock. 0 disables the timeout. The timer applies separately to each lock acquisition, not to total statement runtime; a statement_timeout at the same or lower value will fire first.

lock_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 {#tuning-advice}

> [!TIP]
> **Advice.** These are workload-specific starting points and must be validated with measurements.

| Workload | Guidance |
| --- | --- |
| OLTP | Set lock_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 lock_timeout; preserve a finite guardrail for abandoned work without killing legitimate long scans. |
| Small nodes | Use a conservative finite lock_timeout only when the client or operating system handles termination correctly; verify that maintenance still has a dedicated exception. |
{.full-width}

## Pigsty {#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 | — | — |
{.full-width}

> [!CAUTION]
> **Advice — pending human review.** Fact from the current Pigsty template projection: OLTP: PG9.3–19 Beta 3 unmodified; OLAP: PG9.3–19 Beta 3 unmodified; CRIT: PG9.3–19 Beta 3 unmodified; TINY: PG9.3–19 Beta 3 unmodified. No Pigsty-specific rationale is inferred from an absent override.

## Common pitfalls {#common-pitfalls}

- Changing lock_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 lock_timeout globally without a rollback plan and a client or operational compatibility test.

## Related parameters {#related-parameters}

[`statement_timeout`](/parameters/statement-timeout/) · [`transaction_timeout`](/parameters/transaction-timeout/) · [`idle_in_transaction_session_timeout`](/parameters/idle-in-transaction-session-timeout/) · [`idle_session_timeout`](/parameters/idle-session-timeout/) · [`deadlock_timeout`](/parameters/deadlock-timeout/)

## References {#references}

- [PostgreSQL 19 Beta 3 — lock_timeout](https://www.postgresql.org/docs/19/runtime-config-client.html#GUC-LOCK-TIMEOUT)
- [PostgreSQL 19 release notes](https://www.postgresql.org/docs/19/release-19.html)
- [Machine-readable GUC export](/data/guc.jsonl)