Index degree changed on all indexes to cpu_count on 10.2.0.4

From: Fred Tilly <ftilly_at_btinternet.com>
Date: Thu, 24 Jan 2013 10:27:09 +0000 (GMT)
Message-ID: <1359023229.59012.YahooMailNeo_at_web87401.mail.ir2.yahoo.com>

Hi All,
We have a customer who recently started complaining about performance of our application which had been running smoothly for several years. On looking at some AWR reports the top wait was 'PX Deq Credit: send blkd'

We looked at the explain plans and could see that parallel query was now being used where it had not been before.

On examining the database all indexes on all schemas including sys had there degree set to 8, which also just happens to be the cpu_count for the server.

On looking at other customer environments also on 10.2.0.4 the index degree was set to 1.

The DBA who manages the server has no idea how the indexes all got changed to a degree of 8 and it is not something we had seen before.

The database was originally 10.2.0.2 and had been upgraded to 10.2.0.4 sometime ago.

Anyone got any ideas.

Thanks

Fred

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Received on Thu Jan 24 2013 - 11:27:09 CET