The database retention, for the Audit log, is limited by the retention period, with a maximum of 10 million records.

There is a scheduled running to clean up the records and it is only visible through the database.

select * from scheduler_run_details where job_id = 'com.atlassian.audit.retention.RetentionJobRunner';

Please add the Audit Retention Job Runner to the Scheduled Jobs administration screen for execution visibility and setup.