# 53200 — out_of_memory

> Source-backed reference for PostgreSQL SQLSTATE 53200.
---

# 53200

## At a glance {#at-a-glance}
`53200` is PostgreSQL's out-of-memory condition. Fixed callers include ordinary memory-context allocation, shared-memory and lock-table capacity, extension/statistics-file loading, and WAL-reading processors. The useful diagnosis is the operation and allocation context, not a claim that every memory failure has one cause.

<!-- BEGIN SQLSTATE FACTS: generated by scripts/generate.py; do not edit -->

| Field | Value |
| --- | --- |
| SQLSTATE | `53200` |
| Condition | `out_of_memory` |
| Status | `active` |
| Known present by | `7.4` |
| Locked snapshots | `9.0.23, 9.1.24, 9.2.24, 9.3.25, 9.4.26, 9.5.25, 9.6.24, 10.23, 11.22, 12.22, 13.23, 14.24, 15.19, 16.15, 17.11, 18.6, 19beta3` |
| Macros | `ERRCODE_OUT_OF_MEMORY` |
| Aliases | `—` |

<!-- source facts: data/errcodes/53200.json -->
<!-- END SQLSTATE FACTS -->

## Meaning {#meaning}
The fixed source has several distinct boundaries. `MemoryContextAllocationFailure` reports `out of memory` with the requested size and memory-context name, while `ShmemAlloc` and lock-table setup report `out of shared memory`; the latter can hint at `max_locks_per_transaction`. Extension paths add operation details: `pg_stat_statements` logs `out of memory` with a file-reading detail, and WAL readers report the same primary with an allocation detail. The `pg_stat_statements` branch is `LOG` and returns from its loader, so it is not the same as a client `ERROR` that aborts the current transaction; the core and WAL-reader `ERROR` branches require normal transaction recovery. The two-phase source path is a WAL-reader allocation path, not evidence that reaching `max_prepared_transactions` itself emits 53200.

## Diagnosis {#diagnosis}
Preserve severity, primary, detail, hint, operation, backend, and server log. Determine whether the path was a backend memory-context request, shared-memory/lock-table allocation, file/statistics structure, or WAL reader. For `out of shared memory` with a `max_locks_per_transaction` hint, inspect transaction lock counts and the configured lock-table capacity; increasing it consumes shared memory at startup. Check workload and relevant limits from observation; do not infer a host-wide memory diagnosis from the SQLSTATE alone.

## Response {#response}
Reduce or reshape the operation, release application-side pressure, or adjust the named PostgreSQL capacity after confirming its effect and platform limits. Finish or roll back transactions that hold excessive locks before changing `max_locks_per_transaction`; do not treat that hint as proof of operating-system OOM. For a failed file/WAL/statistics operation, validate the object before retrying. The core/WAL-reader `ERROR` branches leave an explicit transaction failed, so use `ROLLBACK` or `ROLLBACK TO SAVEPOINT` before retrying; autocommit retry is appropriate only after the allocation cause is corrected. The `pg_stat_statements` `LOG` branch is a backend loader path and does not itself require client transaction recovery. OOM and corruption tests are intentionally source-only here; do not force allocator failure on a live host.

## Versions {#versions}
The locked catalogue records this condition from 7.4; cited extension and core paths are PostgreSQL 18.6 source. No OOM runtime was attempted.

## Related {#related}
[`53000`](../53000/), [`53400`](../53400/), [`55000`](../55000/)

## Sources {#sources}
[`contrib/pg_stat_statements/pg_stat_statements.c#L2340-L2350`](https://github.com/postgres/postgres/blob/724edf9bde9d356724ad384a2e196edc3c9f80f7/contrib/pg_stat_statements/pg_stat_statements.c#L2340)

[`contrib/pg_walinspect/pg_walinspect.c#L121-L124`](https://github.com/postgres/postgres/blob/724edf9bde9d356724ad384a2e196edc3c9f80f7/contrib/pg_walinspect/pg_walinspect.c#L121)

[`src/backend/access/transam/twophase.c#L1417-L1420`](https://github.com/postgres/postgres/blob/724edf9bde9d356724ad384a2e196edc3c9f80f7/src/backend/access/transam/twophase.c#L1417)

[`src/backend/utils/mmgr/aset.c#L444-L453`](https://github.com/postgres/postgres/blob/724edf9bde9d356724ad384a2e196edc3c9f80f7/src/backend/utils/mmgr/aset.c#L444)

[`src/backend/utils/mmgr/mcxt.c#L1157-L1167`](https://github.com/postgres/postgres/blob/724edf9bde9d356724ad384a2e196edc3c9f80f7/src/backend/utils/mmgr/mcxt.c#L1157)

[`src/backend/storage/ipc/shmem.c#L151-L162`](https://github.com/postgres/postgres/blob/724edf9bde9d356724ad384a2e196edc3c9f80f7/src/backend/storage/ipc/shmem.c#L151)

[`src/backend/storage/lmgr/lock.c#L2957-L2969`](https://github.com/postgres/postgres/blob/724edf9bde9d356724ad384a2e196edc3c9f80f7/src/backend/storage/lmgr/lock.c#L2957)

The structured [evidence record](../data/evidence/53200.json) records fixed messages and the source/runtime boundary.