Re: Index degree changed on all indexes to cpu_count on

From: Fred Tilly <>
Date: Thu, 24 Jan 2013 14:23:56 +0000 (GMT)
Message-ID: <>

Hi All,
Thanks for all the responses, I had them set parallel_max_servers to 0 so the parallel plans have now stopped. We are just looking to see if we can track down why all the indexes got set to parallel 8. As normal our code is being blamed but that is not the case.



 From: Fred Tilly <> To: "" <> Sent: Thursday, 24 January 2013, 10:27
Subject: Index degree changed on all indexes to cpu_count on  

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 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 and had been upgraded to sometime ago.

Anyone got any ideas.




-- Received on Thu Jan 24 2013 - 15:23:56 CET

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