The following information is captured:
If optimistic locking is switched on, then the operation is guaranteed to have only affected a single record. Therefore, the audit information includes information about the record before and after the operation. The old version of the record is re-read, the old value of each field is compared to the new value, and any field which has changed is included in the audit information, i.e. unchanged fields are filtered out.
If optimistic locking is switched off then for performance reasons the record is not re-read during the update, so the audit information will contain only the new versions of all the fields involved in the update, not a before-after comparison of the record. Also, any non-optimistic updates apart from the 'modify' stereotype can potentially affect more than one record, in which case it is not possible to record a before-after comparison of the update. All the detail fields will be included regardless of whether the new value is different to the old value.
This data can be compressed when using the default auditing handler by specifying the curam.audit.audittrail.datacompressionthreshold property described in the Cúram Configuration Parameters appendix of the Cúram Server Developer's Guide.