Re: Low cardinality in OLTP with high concurrency
From: Mladen Gogala <gogala.mladen_at_gmail.com>
Date: Thu, 26 Mar 2009 09:44:54 +0000 (UTC)
Message-ID: <gqfiqm$u3a$1_at_solani.org>
On Wed, 25 Mar 2009 03:10:01 -0700, Ind-dba wrote:
Date: Thu, 26 Mar 2009 09:44:54 +0000 (UTC)
Message-ID: <gqfiqm$u3a$1_at_solani.org>
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.
-- http://mgogala.freehostia.comReceived on Thu Mar 26 2009 - 04:44:54 CDT