Sample from svrmgrl SHOW SGA:
Total System Global Area 23460696 bytes
Fixed Size 72536 bytes
Variable Size 22900736 bytes
Database Buffers 409600 bytes
Redo Buffers 77824 bytes
Total System Global Area
- Total in bytes of all the sub-divisions that makes up the SGA.
- Contains general information about the state of the database and the instance, which the background processes need to access.
- No user data is stored here.
- This area is usually less than 100k in size.
- This section is influenced by the following init.ora parameters
- See 'Approximating Size of the SGA' section of this article for version specific information.
- Holds copies of data blocks read from datafiles.
size = db_block_buffers * block size
- A circular buffer in the SGA that holds information about changes made to the database.
- Enforced mininum is set to 4 times the maximum database block size for the host operating system.