One of the presenters at recent SQL Server Open World conference in Denmark ( http://www.miracleas.dk/index.asp?page=168&page2=323 ) suggested tuning SQL queries using logical IOs to measure quality of query plan. The IO count is returned for each...

As announced during the PASS Summit 2011 Day One Keynote , we are diving deeper into the world of Big Data by embracing and contributing to the open source community and Hadoop. We’ve had a lot of good coverage on this topic with some examples...

As noted within the Analysis Services 2005 Performance Guide , there are some niche situations where setting the Processing Group property to ByTable provides more optimal processing than the default value of ByAttribute. In a customer scenario, we...

by Denny Lee As many of you know from the various blogs, whitepapers, and conferences from SQLCAT, there is a big obsession or compulsion toward I/O by various members of SQLCAT. If you’re not already familiar with this topic, definitely reference...

Check out the the third of five technical note as part of the Building and Deploying Large Scale SQL Server Reporting Services Environments Technical Note Series: Reporting Services Scale-Out Deployment Best Practices This technical note reviews the...

Author: Sunil Agarwal Reviewers: Kun Cheng, Chuck Heinzelman, Shaun Tinline-Jones, Sanjay Mishra, Kevin Liu When using NOLOCK hint on the table or using read uncommitted isolation level, customers sometimes get surprised when they experience blocking...

We are proud to announce that SQLCAT will continue with the SSAS Maestros course in June and July in Redmond and Madrid. SSAS Maestros 1.2 Courses Join us for a five-day deep-dive course on Analysis Services 2008 R2 UDM and join the SSAS Maestro...

Author: Kun Cheng Reviewers: Sunil Agarwal, Chuck Heinzelman, Shaun Tinline-Jones, Prem Mehra Although not documented very well, the system stored procedures listed below are known to many SQL Server developers and DBAs. For more details, please check...

Author: Sunil Agarwal Reviewers: Kun Cheng, Chuck Heinzelman, Shaun Tinline-Jones, Sanjay Mishra, And Kevin Liu When a transaction T1 modifies a row, it takes an X lock on the row for the duration of the transaction. If another concurrent transaction...

Proper partitioning can improve dramatically the writeback process when dealing with large data sets Author: Nicholas Dritsas Reviewers: Richard Tkachuk, Akshai Mirchandani CASE : Customer is using SQL 2008 and SSAS's writeback abilties to...

Author: Mike Ruthruff Contributors: Gert Drapers, Fabricio Voznika Reviewers: Prem Mehra, Jimmy May, Kun Cheng During a recent performance lab we encountered a large number of waits related to the use of distributed transactions. The specific...

Hello SQL Server Community! My name is Mark Souza and I work on the SQL Server product team and manage all customer programs. One exciting team that I manage is called the SQL Server Customer Advisory team (SQLCAT). This team spends 75% of their time...

Author: Chuck Heinzelman Reviewers: Kevin Cox, Kun Cheng, Michael Thomassy In a recent customer engagement, I was presented with a problem that I have seen in the past and am surprised that I don’t see more often. Take the following table...

Thomas Kejser and I made some significant updates to the SQL Server Analysis Services Performance Guide for SQL Server 2008 - it's available here . Our hope is to keep it alive and make updates as necessary. So if there is something you'd like to see...

Implementing a hierarchy structure in a relational data base normally takes a bit of work. The new SQL Server data type for hierarchyID gives a good shortcut to the old methods, makes it faster to get a solution in place and makes it much easier to maintain...

When we talk to Data Warehouse customers – they often raise questions about the star joins improvements SQL Server 2008. Star join is a set of optimizations that provide some interesting performance gains in data warehouse workload. Instead of digging...

Author: Nicholas Dritsas Reviewers: Thomas Kejser, Stuart Ozer In SSAS 2005 and later, there is a dimension property called ProcessingGroup. It has two values; ByAttribute (default) and ByTable. When you use ByAttribute, SSAS will send a SELECT...

There are many reasons to go to TechEd North America 2010 in New Orleans this year. After all, it is THE event for developers and IT Professionals. And if you want to know more about PowerPivot, here’s yet another reason why you need to go. ...

Interesting observation with table > 1TB We have a project using SQL 2005 with a table that is several terabytes. This table has a varbinary(max) column with an average length of 150k bytes. We needed a second copy of the table on a smaller test...

Author: Darko Sancanin, Nicholas Dritsas Reviewers and contributors: Lubor Kollar, Stuart Ozer, Michael Thomassy Business Case There are currently over 50 million files (over 10 Terabytes of data) that the customer is migrating into a custom...

A new version of the Partition Management Utility for SQL Server is now available on Codeplex at http://sqlpartitionmgmt.codeplex.com/ . This is a tool that helps you create necessary staging tables and indexes and associated check constraints, to support...

Exciting news as earlier this week the SQL Server Product Group announced the release of SQL Server Migration Assistant (SSMA) v5.0! A product with the goal of further simplifying the user experience in automating the migration of Oracle, Sybase, MySQL...

Author : Shaun Tinline-Jones Reviewers : Mike Ruthruff, Sanjay Mishra, Alexei Khalyako Not too long ago an ISV that developed solutions using SQL Server as the RDBMS, asked me how they could query a database as at a point in time. This was a relatively...

As anyone working with partitioned tables knows by now, the process of creating stand-alone ‘staging’ tables to support switching data into or out of a partition can be a management challenge, especially if the design of the partition table or its indices...

Many-to-many dimension relationships in SQL Server 2005 Analysis Services (SSAS) enable you to easily model complex source schemas and provide great analytical capabilities. This capability frequently comes with a substantial cost in query performance...