AWR Snapshot Retention: Missing Automatic Space‑Based Purge Trigger for SYSAUX

Goal: Configure Oracle AWR to automatically purge the oldest snapshots when the SYSAUX tablespace free space falls below a defined threshold, ensuring continuous snapshot collection without manual intervention.

Currently, AWR retention is governed solely by a time‑based interval set through DBMS_WORKLOAD_REPOSITORY.MODIFY_SNAPSHOT_SETTINGS; Oracle does not monitor SYSAUX usage to trigger snapshot deletion. When SYSAUX nears capacity, MMON may fail to write new snapshots, creating gaps in performance data until space is freed or retention is reduced. Administrators must manually run DBMS_WORKLOAD_REPOSITORY.DROP_SNAPSHOT_RANGE or adjust retention to avoid overflow.

Is there a supported way to make AWR retention consider SYSAUX free space? Can a threshold be established via DBMS_WORKLOAD_REPOSITORY or another view to initiate automatic snapshot deletion? What are the compliance or audit implications of purging snapshots based on space rather than a fixed time interval?