Oracle Database / SQL Performance & Memory
ORA-04031: investigate the named shared-memory allocation failure
A shared-memory allocation error can involve fragmentation, workload churn or a specific pool. Preserve the exact pool and allocation details.
Environment and inputs: Oracle Database 19c baseline · SQL*Plus-compatible SQL unless RMAN, DGMGRL, ADRCI or a host shell is specified. Check release, patch level, edition and container first.
Start with this diagnostic
Use the stated SQL, RMAN, DGMGRL or host shell and replace sample names with approved targets. DBA and V$ views need authorized catalog access in the correct container. Do not grant broad privileges for an example.
SELECT pool, name, bytes FROM v$sgastat WHERE name = 'free memory';Read the result
Free-memory rows show current pool accounting, not the exact state when allocation failed. An apparent free total does not guarantee an allocation of the needed size could succeed.
Resolve and verify
Correlate the error with trace details, parse churn and memory configuration. Address the demonstrated cause and use support guidance for a repeatable allocation failure.
Operational precautions
Do not repeatedly flush shared memory or change hidden parameters. A server restart can erase critical incident evidence.