# client_connection_check_interval

> client_connection_check_interval is the PostgreSQL setting that defines the time interval between checks for disconnection while running queries.
---

> [!NOTE]
> **Fact — official short description:** “Sets the time interval between checks for disconnection while running queries.”

## 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 | Connections and Authentication / TCP Settings | Upstream classification |
| Latest boot value | `0` | 0 ms |
{.fields meta="-"}

## Lifecycle {#lifecycle}

| Fact | Value |
| --- | --- |
| First observed | PG14 |
| Present in | PG14–19 Beta 3 |
| Removed in | No |
| Introduction commit | [`c30f54ad732c`](https://git.postgresql.org/gitweb/?p=postgresql.git;a=commit;h=c30f54ad732ca5c8762bb68bbe0f51de9137dd72) — Detect POLLHUP/POLLRDHUP while running queries. |
| Commit date | 2021-04-03 |
| Discussion | [thread 1](https://postgr.es/m/77def86b27e41f0efcba411460e929ae%40postgrespro.ru) |

## Default history {#default-history}

| Versions | Raw `boot_val` | Unit | Human value |
| --- | --- | --- | --- |
| PG14–19 Beta 3 | `0` | `ms` | 0 ms |
{.full-width caption="Measured PG9.0–19 Beta 3 boot defaults"}

## How it works {#mechanism}

client_connection_check_interval sets the time interval between checks for disconnection while running queries. 0 disables connection checks. A nonzero interval lets long-running queries notice a dead client before their next socket write; operating-system support determines whether checks are effective.

client_connection_check_interval 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 | Use a nonzero client_connection_check_interval only when abandoning work after client loss materially saves capacity and the platform supports the check. Measure the polling overhead at the chosen interval. |
| OLAP | Long analytical queries can benefit from periodic disconnect detection because they may otherwise run after a client disappears; the interval does not cap a healthy query's runtime. |
| Small nodes | Leave zero unless orphaned long queries are observed. If enabled, choose an interval that detects waste without adding excessive checks to active queries. |
{.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: PG14–19 Beta 3 unmodified; OLAP: PG14–19 Beta 3 unmodified; CRIT: PG14–19 Beta 3 unmodified; TINY: PG14–19 Beta 3 unmodified. No Pigsty-specific rationale is inferred from an absent override.

## Common pitfalls {#common-pitfalls}

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

## Related parameters {#related-parameters}

[`tcp_keepalives_idle`](/parameters/tcp-keepalives-idle/) · [`tcp_keepalives_interval`](/parameters/tcp-keepalives-interval/) · [`tcp_keepalives_count`](/parameters/tcp-keepalives-count/) · [`tcp_user_timeout`](/parameters/tcp-user-timeout/) · [`authentication_timeout`](/parameters/authentication-timeout/)

## References {#references}

- [PostgreSQL 19 Beta 3 — client_connection_check_interval](https://www.postgresql.org/docs/19/runtime-config-connection.html#GUC-CLIENT-CONNECTION-CHECK-INTERVAL)
- [PostgreSQL 19 release notes](https://www.postgresql.org/docs/19/release-19.html)
- [Machine-readable GUC export](/data/guc.jsonl)