Caching the Same Oracle Table on Two or More TimesTen Databases
For each cache administration user, TimesTen creates a change log table and trigger (as part of what is created to manage caching) in the Oracle database for each cache table in the cache group. A trigger is fired for each committed insert, update, or delete operation on the cached Oracle Database table; the action is logged in the change log table.
When you use the same cache administration user, only one trigger and change log table are created to manage the changes to the base table. Thus, it is efficient and does not slow down the application.
If you create separate cache administration users on each TimesTen database to own the cache group that caches the same Oracle table, then separate triggers and change log tables exist on the Oracle database for the same table: one for each cache administration user. For example, if you have two separate TimesTen databases, each with their own cache administration user, two triggers fire for each DML operation on the base table, each of which are stored in a separate change log table. Firing two triggers and managing the separate change log tables can slow down the application.
The only reason to create separate cache administration users is if one of the TimesTen databases that caches the same table has a slow autorefresh rate or a slow connection to the Oracle database. In this case, having a single cache administration user on both TimesTen databases slows down the application on the faster connection, as it waits for the updates to be propagated to the slower database.