Oracle SGA Components
- Database Buffer Cache: Holds data blocks read from disk
- Keep Buffer Pool: Data blocks that are kept in memory
- Recycle Buffer Pool: Data blocks that are recycled as soon as possible
- Default Buffer Pool: Data blocks managed in the default fashion
- Redo Log Buffer: Holds redo log entries waiting to be written to disk
- Fixed SGA: Contains general information about the state of the database and the instance
- Large Pool: An optional memory area used for backup and restore operations
- Shared Pool: Contains memory structures related to SQL execution
- Library Cache: Contains the shared SQL area and PL/SQL code
- Data Dictionary Cache: An area in the Shared Pool where Oracle stores frequently accessed data dictionary information so that it does not need to be continuously reread from disk
- Control Structures: Library cache: Locks, cache handles, etc.
- Control Structures: Shared pool: character set conversion memory, etc.
- Shared SQL Area: SQL statements and execution plans
- PL/SQL Code: packages, procedures, and functions