Re: Low cardinality in OLTP with high concurrency

From: Mladen Gogala <>
Date: Thu, 26 Mar 2009 09:44:54 +0000 (UTC)
Message-ID: <gqfiqm$u3a$>

On Wed, 25 Mar 2009 03:10:01 -0700, Ind-dba wrote:

> Oracle has improvised on bitmap locks 9i onwards. If there is a single
> process inserting/updating the data, i would suggest you to give it a
> try to use bitmap index.

This is a bad suggestion. Locking a bitmap entry in the index will effectively lock all the rows corresponding to that entry, with disastrous consequences for the concurrency. If anything, single table hash cluster should be considered.

Received on Thu Mar 26 2009 - 04:44:54 CDT

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