Memory Architecture   «Prev 

Three Types of Buffer Pools

The keep buffer pool is used for tables, indexes, and other objects whose data you want kept in memory all the time.

The recycle buffer pool is for objects whose data should be overwritten the moment that it's no longer needed.

Blocks in the default buffer pool are managed in the normal fashion - the least recently used data is aged out as the new data is read in.

Other pools in the SGA

The SGA includes several other pools:
  1. Large pool: Provides memory allocation for various I/O server processes, backup, and recovery, and provides session memory where shared servers and Oracle XA for transaction processing are used.
  2. Java pool: Provides memory allocation for Java objects and Java execution, including data in the Java Virtual Machine in the database.
  3. Streams pool: Provides memory allocation used to buffer Oracle Streams queued messages in the SGA instead of in database tables and provides memory for capture and apply.
Dynamic initialization parameters available for these pools include LARGE_POOL_SIZE, JAVA_POOL_SIZE, and STREAMS_POOL_SIZE.
These are automatically set if MEMORY_TARGET or SGA_TARGET is specified.