DB_CACHE

1.68 DB_CACHE_SIZE

DB_CACHE_SIZE specifies the size of the DEFAULT buffer pool for buffers with the primary block size (the block size defined by the DB_BLOCK_SIZE initialization parameter).

Note:

Oracle recommends against setting this parameter in a PDB. The only shared memory sizing parameter that should be set in a PDB is SGA_TARGET, which specifies the maximum SGA that the PDB can use at any time.

Property	Description
Parameter type	Big integer
Syntax	`DB_CACHE_SIZE =` `integer` `[K \| M \| G]`
Default value	If `SGA_TARGET` is set: If the parameter is not specified, then the default is `0` (internally determined by the Oracle Database). If the parameter is specified, then the user-specified value indicates a minimum value for the memory pool. If `SGA_TARGET` is not set, then the default is either 48 MB or 4 MB * number of CPUs, whichever is greater
Modifiable	`ALTER SYSTEM`
Modifiable in a PDB	Yes
Basic	No

The value must be at least 4M * number of cpus (smaller values are automatically rounded up to this value). A user-specified value larger than this is rounded up to the nearest granule size. A value of zero is illegal because it is needed for the DEFAULT memory pool of the primary block size, which is the block size for the SYSTEM tablespace.