Database Buffer Cache
• Part of the SGA.
• Holds copies of data blocks that are read from data files.
• Shared by all concurrent users.
Redo Log Buffer
• Circular buffer in the SGA.
• Holds information about changes made to the database.
• Contains redo entries that have the information to redo changes made by operations such as DML and DDL.
Shared Pool
• Portion of the SGA.
• Contains:
– Library cache
– Shared SQL area
– Data dictionary cache
– Control structures
Large Pool
Provides large memory allocations for:
• Session memory for the shared server and the Oracle XA interface
• I/O server processes
• Oracle Database backup and restore operations
Java Pool and Streams Pool
• Java pool memory is used in server memory for all session-specific Java code and data in the JVM.
• Streams pool memory is used exclusively by Oracle Streams to:
– Store buffered queue messages
– Provide memory for Oracle Streams processes
