DB_CACHE_SIZE

Parameter type	Big integer
Syntax	DB_CACHE_SIZE = integer [K | M | G]
Default value	48 MB, rounded up to the nearest granule size
Parameter class	Dynamic: ALTER SYSTEM

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 parameter).

The value must be at least the size of one granule (smaller values are automatically rounded up to the granule size). A value of zero is illegal because zero is the size of the DEFAULT pool for the standard block size, which is the block size for the SYSTEM tablespace.