# max_standby_archive_delay

> max_standby_archive_delay — Sets the maximum delay before canceling queries when a hot standby server is processing archived WAL data. Observed in PG9.0–19 Beta 3; its last measured boot default is 30 s in PG19 Beta 3, with sighup context. This is a beta-snapshot fact and can change before PostgreSQL 19 GA.
---

> [!NOTE]
> **Fact — official short description:** “Sets the maximum delay before canceling queries when a hot standby server is processing archived WAL data.”

## Identity {#identity}

| Field | Value | Meaning |
| --- | --- | --- |
| Type | `integer` | Upstream pg_settings type |
| Context | `sighup` | Takes effect after configuration reload |
| Unit | `ms` | Raw unit |
| Range | `-1` – `2147483647` | Raw limits in the last observed version |
| Enum values | — | — for non-enum types |
| Category | Replication / Standby Servers | Upstream classification |
| Latest boot value | `30000` | 30 s |
{.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 | `30000` | `ms` | 30 s |
{.full-width caption="Measured PG9.0–19 Beta 3 boot defaults"}

## How it works {#mechanism}

Sets the maximum delay before canceling queries when a hot standby server is processing archived WAL data. A configuration reload applies a new value; existing work already in flight is not retroactively changed.

While replaying WAL fetched from an archive, recovery may wait up to this accumulated delay for conflicting hot-standby queries before canceling them. It is measured against replay progress, not granted afresh to every query; -1 can let replay lag without bound.

Monitor and change max_standby_archive_delay together with max_standby_streaming_delay, hot_standby, hot_standby_feedback. Validate on the relevant server role and real workload, then use its sighup context to choose session change, reload, or restart; a historical boot default is not the current effective value.

## Tuning advice {#tuning-advice}

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

| Workload | Guidance |
| --- | --- |
| OLTP | Size max_standby_archive_delay from topology, failover roles, slot/subscription count, and reconnect headroom. Test worst-case primary latency, standby replay, and disk retention before production. |
| OLAP | Read standbys and logical subscribers often see long queries or large transactions. Put explicit bounds on replay/apply and monitor lag, worker saturation, slot restart_lsn, and conflict cancellations. |
| Small nodes | Configure only replication capacity that is actually used. Even a small topology needs bounded timeouts and slot lifecycle; unlimited retention is not reliability. |
{.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 | `10min` | different | `10min` |
| OLAP | `10min` | different | `10min` |
| CRIT | `10min` | different | `10min` |
| TINY | `10min` | different | `10min` |
{.full-width}

> [!CAUTION]
> **Advice — pending human review.** Fact from the current Pigsty template projection: OLTP: PG9.0–19 Beta 3 = 10min (dcs); OLAP: PG9.0–19 Beta 3 = 10min (dcs); CRIT: PG9.0–19 Beta 3 = 10min (dcs); TINY: PG9.0–19 Beta 3 = 10min (dcs). Advice, pending human review — Editorial interpretation, pending human maintainer review: the override appears intended to favor bounded read continuity while a standby catches up from archived WAL; confirm it against the current Pigsty templates, hardware fixture, and operational guarantees before publication.

## Common pitfalls {#common-pitfalls}

- Changing it on the wrong primary, standby, sender, or subscriber role.
- Watching only configured bytes/time instead of actual lag, slot position, and worker state.
- Failing over to a node that lacks the old primary's capacity or prerequisites.
- Using infinite waits or WAL retention to hide a failed consumer.

## Related parameters {#related-parameters}

[`max_standby_streaming_delay`](/parameters/max-standby-streaming-delay/) · [`hot_standby`](/parameters/hot-standby/) · [`hot_standby_feedback`](/parameters/hot-standby-feedback/) · [`recovery_min_apply_delay`](/parameters/recovery-min-apply-delay/) · [`primary_conninfo`](/parameters/primary-conninfo/) · [`primary_slot_name`](/parameters/primary-slot-name/)

## References {#references}

- [PostgreSQL 19 Beta 3 — max_standby_archive_delay](https://www.postgresql.org/docs/19/runtime-config-replication.html#GUC-MAX-STANDBY-ARCHIVE-DELAY)
- [PostgreSQL 19 release notes](https://www.postgresql.org/docs/19/release-19.html)
- [Machine-readable GUC export](/data/guc.jsonl)