关于DB_CACHE_SIZE的一点内容

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 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.