CREATE CLUSTER

Create a cluster of tables.

Syntax:

CREATE CLUSTER schema.cluster(col1 type, col2 type...)
options [ROWDEPENDENCIES|NOROWDEPENDENCIES] [CACHE|NOCACHE] ;

Options:
The options used with this command can be any combination of the following

PCTUSED int
PCTFREE int
INITRANS int
MAXTRANS int
SIZE int K | M
TABLESPACE tablespace_name
STORAGE storage_clause
INDEX | [SINGLE TABLE] HASHKEYS int [HASH IS expression]
PARALLEL parallel_clause

If the PARALLEL clause is used it should be the last option.

SIZE dictates the amount of space (in bytes) reserved to store all rows with the same cluster key value or the same hash value.

Specify INDEX to create an indexed cluster.

Specify the HASHKEYS clause to create a hash cluster and specify the number of
hash values for a hash cluster.

Specify CACHE if you want the blocks retrieved for this cluster to be placed at the most recently used end of the least recently used (LRU) list in the buffer cache when a full table scan is performed. This may improve performance for small lookup tables.

The ROWDEPENDENCIES setting is primarily used to allow parallel propagation in a replicated database.