About Log-Based and Trigger-Based Read-Only Cache Groups

Log-based read-only cache groups provide an alternative approach to trigger-based read-only cache groups by leveraging redo logs to synchronize data between Oracle and TimesTen. This method is ideal for both static and dynamic cache groups, where the data is continuously refreshed and synchronized from Oracle. It enables automatic refresh and asynchronous data propagation from Oracle to TimesTen by reading changes from the Oracle logs. Since it uses redo logs, it reduces the load on the Oracle database. It is ideal for scenarios when there is a high volume of data and the data is used frequently. This cache group is perfect for high-performance read applications that need real-time access to Oracle data with minimal delay and overhead.

A trigger-based read-only cache group synchronizes data changes between the Oracle database and the TimesTen cache using database triggers instead of redo logs. Oracle triggers capture changes such as inserts, updates, and deletes on the source tables, which are then propagated to TimesTen. This lowers DML latency in propagating changes to the TimesTen cache. These triggers activate immediately when data changes occur, enabling caching to detect and respond. This method adds overhead to transactions, making it harder to maintain.