System Global Area (SGA)
Definition - What does System Global Area (SGA) mean?
Techopedia explains System Global Area (SGA)
Oracle uses the automatic memory management feature to calculate and allocate memory to different SGA areas. Initialization parameters may also be used to manually allocate memory to individual SGA areas.
SGA components are as follows:
- Dictionary cache: Holds data dictionary table information, such as information regarding accounts, segments, data files, tables and privileges
- Redo log buffer: Includes information about committed transactions that have not yet been written to online redo log files
- Buffer_cache: Holds a copy of data blocks read from data files
- Shared pool: Holds a cache of parsed and commonly used Structured Query Language (SQL) statements
- Java pool: Parses Java statements