Re: Hash Cluster Bennies

According to Oracle, most data just isn't structured to take advantage of
hash clustering.

tables must:

     have  columns in common
     be  often used together
     be often stored  in  the same data  blocks

So, if you have a (mostly) read-only tablespace with properly-structured data,
you might do well to use clustering. The only example I've seen of clustered data involved results from a mass-screening exercise - a fixed
number of tests for every tested compound.

Clusters can reduce performance of inserts, updates, deletes and full tables scans while improving performance of queries. Received on Mon Jul 31 1995 - 00:00:00 CEST