Enable Unified Auditing with Syslog - Audit still get inserted to unified_audit_trail

Hi,

configuration question about Unidfied Auditing. I've followed the document to send Auditing to syslog. Auditing is sent to syslog, which is good, the question is more this, since i''m sending it syslog, why does the audit still get inserted into the table unified_audit_trail? Should the parameter audit_trail = Os push it only to syslog or im missing a anither parameter or i need to implement a purge job?