Oracle Core: Essential Internals for DBAs and Developers

Summary

When you compare the buffer cache with the shared pool, you can recognize that they have to handle similar problems and have adopted similar strategies as a consequence. The function and behavior of the cache buffers LRU chains latch is similar to that of the shared pool latch; and we can also see similarities between the cache buffers chains latches and the library cache latches.

The shared pool latch controls the movement of memory from the free pool to the used pool, moving chunks on and off an LRU list; the cache buffers LRU chains latch controls the movement of buffer memory between the auxiliary (don’t mind too much if we forget the block) list and the main (recently used blocks) list. The library cache latches serialize access ...