Synopsis

Values:0 to derived

Default:8

Specifies the number of buffers added to each batch of buffers that DBWR writes in order to advance checkpoint processing. When set to a low value, DB_BLOCK_CHECKPOINT_BATCH prevents the I/O system from being flooded with checkpoint writes, thus allowing other modified blocks to be written to disk. Increasing this parameter allows checkpoints to complete more quickly.

Generally, this parameter should be set to a value that allows the checkpoint to complete before the next log switch takes place. If a log switch takes place every 20 minutes, for example, this parameter should be set to a value that allows checkpointing to complete within 20 minutes. Setting DB_BLOCK_CHECKPOINT_BATCH to causes the default value to be used. If the value specified for this parameter is overly large, Oracle limits it (without notification) to the number of blocks that can be written in a DBWR write batch.