SGA_MIN_SIZE

1.292 SGA_MIN_SIZE

SGA_MIN_SIZE indicates a possible minimum value for SGA usage of a pluggable database (PDB).

Property	Description
Parameter type	Big integer
Syntax	`SGA_MIN_SIZE =` `integer` `[K \| M \| G]`
Default value	`0`
Modifiable	`ALTER SYSTEM`
Modifiable in a PDB	Yes
Range of values	0 to 50% of `SGA_TARGET`
Basic	No
Oracle RAC	The same value must be used for all instances.

Setting this parameter at the CDB level has no effect.

Note:

To be able to use Resource Manager in a CDB to control the amount of memory each PDB can use:

The NONCDB_COMPATIBLE initialization parameter must be set to FALSE at the CDB level (in the root of the CDB).
The MEMORY_TARGET initialization parameter must not be set at the CDB level.
A value for SGA_TARGET must be set at the CDB level.

If SGA_TARGET is not set at the CDB level, then setting SGA_MIN_SIZE in a PDB has no effect. You will not receive an error message, and the PDB’s SGA_MIN_SIZE value will not be enforced.
You must set the SGA_MIN_SIZE value to a value that meets these requirements:
- In a PDB, to a value that is less than or equal to 50% of the value of SGA_TARGET in the PDB
- In a PDB, to a value that is less than or equal to 50% of the value of SGA_TARGET at the CDB level
- In a PDB, to a value that is less than the value of SGA_MAX_SIZE at the CDB level
- Across all the open PDBs in a CDB, the sum of SGA_MIN_SIZE values must be less than or equal to 50% of the managed SGA total at the CDB level. Managed SGA is DB_CACHE_SIZE plus SHARED_POOL_SIZE.
When you set SGA_MIN_SIZE in a PDB to a value that does not meet these requirements, you receive an error.

Note:

This initialization parameter is available starting with Oracle Database 12c Release 2 (12.2.0.1).