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.

Birds of a feather will gather together - Robert Burton

Related Commands:

CLUSTER - ALTER

Related Views:

 DBA_CLUSTERS        ALL_CLUSTERS       USER_CLUSTERS 
 DBA_DATA_FILES


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