Comments on: Missing Indexes DMV

By: James L

James L — Thu, 15 Dec 2011 15:55:38 +0000

Thanks for this…using it right now!

By: Derek Dieter

Derek Dieter — Fri, 16 Sep 2011 20:02:19 +0000

Hi Praful,

What sounds like is happening, is during peak time the data returned for the query is not in memory and needs to be retrieved from disk. It definitely sounds like you are missing indexes or possibly using table variables. You should get the execution plan for the query and see if there are any indexes missing.

Derek

By: praful

praful — Tue, 06 Sep 2011 08:52:33 +0000

my stored proecedure run 4 min off peak time and 30 mins in peak time, i am not able to find the cause for 30 mins duration.Please tell me the various ways to find the bottleneck cause solution.
we has transaction replication setup on the same server.

By: Curt Mader

Curt Mader — Sun, 20 Feb 2011 17:57:13 +0000

Thanks Derek!

By: Derek Dieter

Derek Dieter — Thu, 17 Feb 2011 20:50:13 +0000

Hi Curt,

This is because a lot of times, the indexes are suggested in order to avoid a “bookmark lookup”. In other words, the index used to find the fields does exist, however it needs to go back to the clustered index (or heap) in order to get the required columns. The query optimizer does not like this scenario, so it will often suggest new indexes that contain “include” columns. These suggestions can be misleading. The other problem with the suggestions is that it does not take into account the fact that you may need to change your clustered index.

With all that said, the index suggestions are still very useful and something I find myself considering a lot. Much better than the suggestions in SQL 2000..