Integer 

Static 

Operating system dependent 

2048 to 32768, but your operating system may have a narrower range 

You must set this parameter for every instance, and multiple instances must have the same value 

CAUTION: Set this parameter at the time of database creation. Do not alter it afterward. 

DB_BLOCK_SIZE specifies the size in bytes of Oracle database blocks. Typical values are 2048 and 4096. The value for DB_BLOCK_SIZE in effect at CREATE DATABASE time determines the size of the blocks. The value must remain set to its original value.

If you are using Oracle Parallel Server, this parameter affects the maximum value of the FREELISTS storage parameter for tables and indexes. Oracle uses one database block for each freelist group. Decision support system (DSS) and data warehouse database environments tend to benefit from larger block size values. See Also:

• Oracle8i Designing and Tuning for Performance and Oracle8i Administrator's Guide for information on setting this parameter.

• Oracle8i SQL Reference for information on freelist groups.

• Oracle8i Designing and Tuning for Performance for more information on the DSS and data warehouse environments.

• Oracle8i Concepts for information on block size in general.