DB_CACHE_SIZE参数定义

刘泽宇

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 4MB * number of CPUs * granule size, 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:

DB_BLOCK_BUFFERS cannot be combined with the dynamic DB_CACHE_SIZE parameter; combining these parameters in the same parameter file will produce an error.