Multiple Block Sizes

Multiple Block Sizes

9i supports multiple blocksizes within one database. The original block size specified is called the default blocksize or the standard blocksize. An Oracle database can have up to four additional blocksizes. Oracle’s allowable blocksizes are 2, 4, 8, 16, and 32 Kilobytes.

The SYSTEM and temporary tablespaces must be of the standard blocksize, and all partitions of a partitioned table must be of the same blocksize.

For each nonstandard blocksize you intend to use, you must set one initialization parameter to provide its cache. Here’s an example for an 8K blocksize:

DB_8K_CACHE_SIZE = 8M

Now you can create tablespace(s) with the new blocksize simply by appending the keywords BLOCKSIZE 8K to the CREATE TABLESPACE statement. The dictionary view DBA_TABLESPACES has the new column BLOCK_SIZE to track this parameter.