About Purging Audit Trail Records
You can use a variety of ways to purge audit trail records.
You should periodically archive and then delete (purge) audit trail records. You can purge a subset of audit trail records or create a purge job that performs at a specified time interval. Oracle Database either purges the audit trail records that were created before the archive timestamp, or it purges all audit trail records. You can purge audit trail records in both read-write and read-only databases.
The purge process takes into account not just the unified audit trail, but audit trails from earlier releases of Oracle Database. For example, if you have migrated an upgraded database that still has operating system or XML audit records, then you can use the procedures in this section to archive and purge them.
To perform the audit trail purge tasks, you use the DBMS_AUDIT_MGMT PL/SQL package. You must have the AUDIT_ADMIN role before you can use the DBMS_AUDIT_MGMT package. Oracle Database mandatorily audits all executions of the DBMS_AUDIT_MGMT PL/SQL package procedures.
If you have Oracle Audit Vault and Database Firewall installed, the audit trail purge process differs from the procedures described in this manual. For example, Oracle Audit Vault archives the audit trail for you. Note: Oracle Database audits all deletions from the audit trail, without exception.