DB_BLOCK_CHECKING
DB_BLOCK_CHECKING
controls whether Oracle performs block checking for data blocks. When this parameter is set to true
, Oracle performs block checking for all data blocks. When it is set to false
, Oracle does not perform block checking for blocks in the user tablespaces. However, block checking for the SYSTEM
tablespace is always turned on.
Oracle checks a block by going through the data on the block, making sure it is self-consistent. Block checking can often prevent memory and data corruption. Block checking typically causes 1% to 10% overhead, depending on workload. The more updates or inserts in a workload, the more expensive it is to turn on block checking. You should set DB_BLOCK_CHECKING
to true
if the performance overhead is acceptable.