12.7.3. Auditing Strategies
12.7.3.1. About Auditing Strategies
Auditing strategies define how audit information is persisted, queried and stored. There are currently two audit strategies available with Hibernate Envers:
- Default Audit Strategy
- This strategy persists the audit data together with a start revision. For each row that is inserted, updated or deleted in an audited table, one or more rows are inserted in the audit tables, along with the start revision of its validity.Rows in the audit tables are never updated after insertion. Queries of audit information use subqueries to select the applicable rows in the audit tables, which are slow and difficult to index.
- Validity Audit Strategy
- This strategy stores the start revision, as well as the end revision of the audit information. For each row that is inserted, updated or deleted in an audited table, one or more rows are inserted in the audit tables, along with the start revision of its validity.At the same time, the end revision field of the previous audit rows (if available) is set to this revision. Queries on the audit information can then use between start and end revision, instead of subqueries. This means that persisting audit information is a little slower because of the extra updates, but retrieving audit information is a lot faster.This can also be improved by adding extra indexes.
For more information on auditing, refer to Section 12.7.2, “About Auditing Persistent Classes”. To set the auditing strategy for the application, refer here: Section 12.7.3.2, “Set the Auditing Strategy”.
