DB_CACHE_SIZE

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
Basic	No

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).

The value must be at least 4M * number of cpus * granule size (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.

Note:

1. This parameter was introduced in Oracle9i.

2. Query for the current value of the parameter

select name, value, isdefault, isses_modifiable, issys_modifiable,

isinstance_modifiable, isdeprecated, description

from v$parameter where upper(name) = ‘DB_CACHE_SIZE’;

NAME	VALUE	IS DEFAULT	ISSES_ MODIFIABLE	ISSYS_ MODIFIABLE	ISINSTANCE_ MODIFIABLE	IS DEPRECATED	DESCRIPTION
db_cache_size	10737418240	FALSE	FALSE	IMMEDIATE	TRUE	FALSE	Size of DEFAULT buffer pool for standard block size buffers

Oracle initializatoin parameters