When to use lock_sga
In practice, the lock_sga parameter is only needed when you have an over-stressed server with RAM paging, and its always a better idea to add more RAM than to lock-in the SGA by making it non-swappable.The lock_sga parameter is also useful in cases with multiple instances on an over-stressed server, where the lock_sga=true instance is to have priority over memory usage, at the expense of the other SGAs.
