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Home -> Community -> Usenet -> c.d.o.misc -> Re: Shrinking an index??
Ruedi Aschwanden <ruedi_at_multiactive.com> wrote:
>Can you comment on how performance was affected?
I have seen no degradation. Unfortunately I don't have any hard stats to say that it is x% faster.
>> How about using a BITMAP index found in 7.3.2.3? It has saved me
>> great amounts of disk space. A number of my indexes were over 400 Meg
>> in size before changing to BITMAP and are now around 69 Meg each.
>> BITMAPs are useful for 'low cardinality' indexes (ie. those with
>> low number of distinct values compared to the total number of rows in
>> the table). To find out about the cardinality do an ANALYZE on the
>> index then check the DISTINCT_KEYS column in DBA_INDEXES.
>> It is well worth the effort of upgrading to 7.3.2.3!