SQLCAT.Com – eBook Downloads

As of September 1, 2013 we decided to remove SQLCAT.COM site and use MSDN as the primary vehicle to post new SQL Server content. This was done to minimize reader confusion and to streamline content publication.  MSDN SQLCAT blogs already includes most SQLCAT.COM Content and will continue to be updated with more SQLCAT learnings.  You can also… Read more

Writing New Hash Functions for SQL Server

Author: Thomas Kejser Contributors/Reviewers: Alexei Khalyako, Jerome Halmans, Fabricio Voznika, Sedat Yogurtcuoglu, Mike Ruthruff, Tobias Ternstrom and Steve Howard In this blog, I will explore ideas for extending SQL Server with new, fast hash functions. As will be shown, the high speed, built in functions CHECKSUM and BINARY_CHECKSUM are not always optimal hash functions, when… Read more

“QUOTED_IDENTIFIER” causes Unexpected Query Plan for Persisted Computed Column query

Author: Shaun Tinline-Jones Technical Reviewers: Thomas Kejser, Steve Howard, Jaime Alva Bravo, Kun Cheng, Jimmy May Note: Validation for this post was performed in the SQL CAT Customer Lab on an HP Proliant DL580 G7, Intel Xeon Nehalem E7-4870 2.40 GHz 4 socket, 10 physical cores, 20 logical cores for a total of 40 physical… Read more

Optimize Recursive CTE Query

Author: Shaun Tinline-Jones Reviewers: Lubor Kollar; Conor Cunningham; Steve Howard; Kun Cheng; James Podgorski; Jimmy May; Joseph Sack; Welly Lee; Neeraj Joshi; Keith Bauer Introduction We recently assisted a global ISV to address a performance issue related to a poor performing recursive CTE (Common Table Expression). The ISV wanted the query that was running in… Read more

Linked Servers to SQL Azure

Authors:  Kevin Cox & Michael Thomassy Contributors: Lubor Kollar Technical Reviewers: Shaun Tinline-Jones, Chuck Heinzelman, Steve Howard, Kun Cheng, Jimmy May Overview   Connecting directly to a SQL Azure database from a reporting tool (like Microsoft Excel and PowerPivot, or SQL Server Reporting Services) from your desktop or local data center is possible using a… Read more

Character data type conversion when using SQL Server JDBC drivers

Author: Kun ChengReviewers: Wanda He, Kevin Cox, Michael Thomassy, Peter Scharlock In a recent customer engagement, I ran into an interesting situation, which I’d like to share, especially with SQL Server users using Microsoft JDBC drivers. It started with typical SQL Server performance tuning exercise to identify the most expensive queries running in SQL Server…. Read more

New Best Practices Articles Published – Analysis Services Many-to-Many Dimensions: Query Performance Optimization Techniques

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 due to the runtime join required by Analysis Services to resolve many-to-many queries. This best practices white paper discusses three many-to-many… Read more

SSAS small/big query interaction

Default SSAS behavior can sometimes result in small queries being slowed down by concurrently running big queries. Recently in working with a customer, we observed the most common queries when run by themselves took about 1 second and some ad-hoc queries against their 110 GB cube took about 3 minutes.  When running both together, small… Read more

Using unformatted cell values it may improve query performance

If a report does not use formatted cell values, query time can be reduced.  An example is a Reporting Services report that does its own formatting and therefore would not use the formatted values from SSAS.  By returning only the value of the cell and not its formatted value in MDX, you can achieve better… Read more