Re: When to use bitmap indexes

On Sat, 22 Sep 2001, jimdavis_at_iprolink.ch wrote:

> "NB: Bitmaps and changes to the tables do NOT mix at all well"

He's saying that when columns that have indexes on them get updated, the indexes get updated as well. Updates to bitmap indexes are _very_ expensive. That's why "do NOT mix ..." In my experience, bitmap indexes are used for query only tables, ie, reporting tables.

Here is online documentation on bitmap indexes for 8.1.7 http://otn.oracle.com/docs/products/oracle8i/doc_library/817_doc/server.817/a76965/c08schem.htm#5381

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Galen Boyer
Everyone in town, now, they probably all agree,
I'm _lying_ in the bed I made.