Most Recent Blog Posts

Apr 09, 2011

Why can a database snapshot run out of space?1

A database snapshot does not reserve space when it is created so it is quite possible for it to run out of space (and hence become unusable)....More
Apr 04, 2011

Size-of-data operations when adding and removing columns1

There are two main sets of column metadata maintained by SQL Server – one for the relational definition of the table, and one for how the columns are....More
Mar 22, 2011

When do checkpoints occur for tempdb?2

A checkpoint has two purposes: firstly to write out data pages so that what is in the data files is up-to-date with what is in the log, so there is....More
Mar 11, 2011

When did you last test your disaster recovery strategy?

When did you last test your SQL Server disaster recovery strategy? It’s all very well having a strategy, but how do you know it works?....More
Mar 01, 2011

Why does my transaction log grow but my log backups don’t?

Whenever a database is changed, transaction log records are generated that describe the changes that are made. If something goes wrong with the....More
Boxer with red boxing gloves
Feb 20, 2011


Is it better to use OPTION (RECOMPILE) rather than dynamic SQL? Both options are likely to recompile each time, and forcing recompilation with OPTION....More
Feb 13, 2011

Problems with Local Variables

Using local variables in statements and procedures can cause poor cardinality estimates. Alternative solutions can include rewriting the query to use....More
Jan 28, 2011

Determine the Performance Effect of Query Plan Changes

How can you tell whether the stored procedure query plan changes you make actually improve your CPU time and logical reads?....More
Jan 24, 2011

How Does Index Fragmentation Affect SELECT Performance?

To preserve application architecture, we want to retain the GUID as a primary key when clustering on a new INT column that’s not used by the....More
Jan 13, 2011

How Can Fixing Database Corruption Shrink a Database?

How can I repair database corruption as quickly as possible if I don’t have workable backups? And after repairing some database corruption, my....More
Dec 27, 2010

Why Doesn’t New Hardware Enhance SQL Server Performance?2

We recently implemented a new server with faster CPUs, more cores, and double the amount of memory. We restored our production database to it and....More
Dec 13, 2010

Choosing Default Sizes for Your Data and Log Files

Once you’ve chosen how you’re going to manage your transaction log, you can do capacity planning. Part of why you need to determine how you’re going....More
Dec 01, 2010

When a Delete isn’t Really a Delete…

When I delete lots of data from a table with a clustered index using a DELETE statement, the table size isn’t reduced like I would expect it to be....More
Nov 26, 2010

Should I Optimize My SQL Server Instances for Ad Hoc Workloads?

In general, I recommend that the SQL Server 2008 configuration option be enabled on all my customers’ servers. The original idea behind the option....More
Nov 12, 2010

Is SQL Server Up-Level Compatible?

Q: Why can’t I restore a database from SQL Server 2008 to a SQL Server 2005 instance? It doesn’t work even when I use the 90-compatibility mode. A:....More

Paul S. Randal

Paul Randal worked on Microsoft's SQL Server team for nine years in development and management roles, writing many of the DBCC commands. Randal was ultimately responsible for SQL Server 2008'...

Kimberly L. Tripp

Kimberly L. Tripp has been working with SQL Server since 1990, and she’s worked as a consultant, trainer, speaker, and writer specializing in core SQL Server performance tuning and availability...
What's SQL Server Questions Answered?

Practical tips and answers to many of your questions about SQL Server including database management and performance issues.

Blog Archive

Sponsored Introduction Continue on to (or wait seconds) ×