File->System Configuration->Audit Logging

If Audit Logging is employed, you should remember that this will create records in the AUDITLOGGING Table

Current records can be displayed via General->Inquiries->Inquiry - Audit Logging

Audit Logging allows you to identify a specific field in an Ostendo Database which, when a record is added, changed, or deleted and this field is contained in that record then an Audit Log is created that records the old value and the new value along with the User that carried out the action and the Date and Time it was carried out

This function is extremely useful when trying to determined who or when a field value was written or Amended. Audit Logging should be used sparingly for a specific purpose and then removed once you have determined what you need. If ignored, this could significantly impact on the database size.

 NB: Turning off this setting simply means that no more records will be logged, however previous records will remain.

The SQL below will enable you to determine the number of  records in this table:

Select Count(sysuniqueid) from auditlogging

For a more accurate assessment of the storage implications of this, we suggest you refer to the article 

https://developmentx.zohodesk.com.au/portal/en/kb/articles/determining-record-count-and-table-sizes

If you do intend to delete records from this table (using SQL), you should always create a Backup of the database first and then perform a Firebird Validation / Backup and Restore after the deletion. We suggest if you are not confident with SQL, that you enlist the services of a Developer Partner to provide you with an appropriate script to delete unwanted Logging records.