# log_rotation_age

> log_rotation_age is the PostgreSQL setting that defines the amount of time to wait before forcing log file rotation.
---

> [!NOTE]
> **Fact — official short description:** “Sets the amount of time to wait before forcing log file rotation.”

## Identity {#identity}

| Field | Value | Meaning |
| --- | --- | --- |
| Type | `integer` | Upstream pg_settings type |
| Context | `sighup` | Takes effect after configuration reload |
| Unit | `min` | Raw unit |
| Range | `0` – `35791394` | Raw limits in the last observed version |
| Enum values | — | — for non-enum types |
| Category | Reporting and Logging / Where to Log | Upstream classification |
| Latest boot value | `1440` | 1 d |
{.fields meta="-"}

## Lifecycle {#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 {#default-history}

| Versions | Raw `boot_val` | Unit | Human value |
| --- | --- | --- | --- |
| PG9.0–19 Beta 3 | `1440` | `min` | 1 d |
{.full-width caption="Measured PG9.0–19 Beta 3 boot defaults"}

## How it works {#mechanism}

log_rotation_age sets the amount of time to wait before forcing log file rotation. 0 disables time-based creation of new log files. The collector opens a new file after the interval; zero disables this trigger but leaves size-based or external rotation possible.

log_rotation_age is a SIGHUP-context setting: a configuration reload activates the new server value without a restart; subsequent operations that consult it use the refreshed value.

The active path is composed from log_destination, logging_collector or syslog/eventlog, file naming and permissions, rotation triggers, and external shipping or retention.

## Tuning advice {#tuning-advice}

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

| Workload | Guidance |
| --- | --- |
| OLTP | Set log_rotation_age from the maximum time a file may remain open and the shipping/retention boundary. Confirm that the filename pattern creates a distinct or intentionally reusable name at that interval. |
| OLAP | Long analytical bursts do not require a different clock by themselves; choose an interval that lets downstream systems close and ingest files predictably without producing impractically large objects. |
| Small nodes | Prefer a simple daily or shorter interval that keeps failure blast radius bounded. Zero disables time rotation and is safe only when size-based or external rotation is authoritative and tested. |
{.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 | `1d` | same as boot | `'1d'` |
| OLAP | `1d` | same as boot | `'1d'` |
| CRIT | `1d` | same as boot | `'1d'` |
| TINY | `1d` | same as boot | `'1d'` |
{.full-width}

> [!CAUTION]
> **Advice — pending human review.** Fact from the current Pigsty template projection: OLTP: PG9.0–19 Beta 3 = 1d (dcs); OLAP: PG9.0–19 Beta 3 = 1d (dcs); CRIT: PG9.0–19 Beta 3 = 1d (dcs); TINY: PG9.0–19 Beta 3 = 1d (dcs). Advice, pending human review — Editorial inference: Daily rotation matches the weekday filename cycle and creates predictable operational boundaries.

## Common pitfalls {#common-pitfalls}

- Editing log_rotation_age without reloading configuration and verifying the effective value and subsequent behavior.
- Combining incompatible destination, collector, filename, and rotation assumptions and then losing or overwriting logs.
- Failing to monitor a full or unwritable log target, which can block logging or database activity depending on the path.
- Changing log_rotation_age globally without a rollback plan and a client or operational compatibility test.

## Related parameters {#related-parameters}

[`logging_collector`](/parameters/logging-collector/) · [`log_destination`](/parameters/log-destination/) · [`log_directory`](/parameters/log-directory/) · [`log_filename`](/parameters/log-filename/) · [`log_rotation_size`](/parameters/log-rotation-size/)

## References {#references}

- [PostgreSQL 19 Beta 3 — log_rotation_age](https://www.postgresql.org/docs/19/runtime-config-logging.html#GUC-LOG-ROTATION-AGE)
- [PostgreSQL 19 release notes](https://www.postgresql.org/docs/19/release-19.html)
- [Machine-readable GUC export](/data/guc.jsonl)