What can replace Oracle sequence on RAC environment?
There are many production tables in Oracle RAC environment.
In order to log all tables change, there is a table named "LOG_QUEUE". If there is a INSERT/UPDATE/DELETE on a table, the row is copied to the "LOG_QUEUE" table.
Problem is the "LOG_QUEUE" table has a key that has beein genearting by Oracle sequence because the change order in database is very important in the "LOG_QUEUE" table. It was okay in Single Instance. But, soon it should work on RAC environment having two instances.
The Oracle sequence we use has "ORDER" and "CACHE" options. In RAC environment, it will make performance issue.