While deciding Index type you should consider, whether your database os
olap or oltp,
For datawarehouse type databases you can use bitmap index which takes
less size, if values are repeated in key column, it also improves the
performance since data is read only in warehouse.
But if you are working on transactional database go for b-tree indexes
since locking could be a problem in bitmap index, since in bitmap locks
are more tight (for more rows than you are accessing) it will hamper
your concurrency.


Lav Pandit | System Analyst | GIOS


-----Original Message-----
From: Manish Sahay
[mailto:oracledba-ezmlmshield-x5575007.[Email address protected]
Sent: Thursday, September 06, 2007 4:12 PM
To: LazyDBA Discussion
Subject: Oracle Index


Hi All,

While creating Indexes on tables, what are things to be considered? When
to use Btree/Bitmap type of indexes, i.e. deciding factors to use the
definite type of index

Manish Kumar Sahay


A journey of a thousand miles begins with a single step." Make sure you
are there and on time !!


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