Table variables and row estimations – Part 2

Hello again, On my previous post, we covered how the Query Optimizer handles row estimation when using Table variables under specific conditions. Following up on that, I will demonstrate other scenarios where the Query Optimizer must try to optimize queries when no statistics and histograms are available. In the 2nd example of the series I…


Table variables and row estimations – Part 1

Hello all, The subject of estimated rows vs. actual rows in plan execution has a lot of impact in query performance, and the source of these skews can be quite diverse, from outdated statistics, to incorrect sampling, or the inability of the query processor to know the value of certain variables at compile time, just…

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Upgrading Data Quality Services (DQS) from RTM to SQL Server 2012 SP1

Hello everyone,   Today Data Quality Services (DQS) team release a post about upgrading DQS RTM to SQL Server 2012 SP1. Please refer to http://blogs.msdn.com/b/dqs/archive/2012/11/29/upgrading-dqs-to-sql-server-2012-service-pack-1-sp1-release.aspx for instructions. If have any issues using this article please let us know!   See you next time! Disclaimer: I hope that the information on these pages is valuable to you. Your…


About Maintenance Plans – grooming SQL Server

Hello all, I admit I’m not a big fan of Maintenance Plans (the feature that goes by that name) mainly because of its “do or die” approach. So, it was not by chance that I wrote and keep updating the AdaptiveIndexDefrag procedure. Good maintenance (or lack thereof) may be the difference between good and bad…


SQL Swiss Army Knife #11.1 – Locking, blocking and active transactions

EDIT (12-04-2013): Added page type information (PFS; GAM or SGAM) when wait type is PAGELATCH_ or PAGEIOLATCH_ . EDIT (23-05-2013): Fixed parse page issue. EDIT (17-10-2013): Added memory grant info, statements to blocking and blocked sections of blocking report, and fixed head blocker info. EDIT (09-12-2013): Fixed blocking section showing non-blocked sessions also EDIT (09-04-2014): Added information to…

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Take most of Reporting Services Logs with Excel 2013

Hi everybody. It’s been a while since I have posted in this blog about Reporting Services Logs and today we are going to put some of it in practice. The purpose of this post is to use the newest version of Excel 2013 Customer Preview that can be found here and use PowerPivot and Power View…


A practical example on missing a filtered index

Hello all, Last week I did a brief presentation on SQLPort about hinting the database engine. What’s related here is that during the presentation, when I was discussing index hints, an attendee asked me about the usefulness of Filtered Indexes in certain scenarios, and how the database engine would behave differently in SQL Server 2008R2…


SQL Swiss Army Knife #12 – Index information galore!

EDIT (06/06/2012): Added script for all databases (may cause performance problems in large servers) and current database only. also fixed issue with partition aligned indexes. EDIT (19/11/2012): Added Heap information and redesigned duplicate and redundant index search. EDIT (18/12/2012): Fixed miscellaneous issues and added schema information. EDIT (20/01/2013): Added index related information. EDIT (27/02/2013): Fixed…


SQL Server 2012 new high VLFs warning: Important update

Hello all, If you follow this blog, this is another post on VLFs, a topic I’ve covered several times before. If you want to read more about it just click here. Also, all scripts in the VLF posts have been updated to support SQL server 2012. So, back in October I posted about the new…


Free SQL Server 2012 eBook giveaway

Hello all, Just to give you the heads-up that Microsoft has made available a new free eBook entitled “Introducing Microsoft SQL Server 2012”. Right now you can download the PDF version, but very soon an EPUB and MOBI versions will also be available. EDIT (26-03-2012): PDF, EPUB and MOBI versions are available now! Hope you…