Most Recent Blog Posts

missing blue puzzle piece
Jul 31, 2012

Recovering a database with a missing transaction log

Usually when a database has open transactions and the server crashes, crash recovery will run on the affected database and roll back the open....More
Recovery road sign with arrow
Jul 27, 2012

Is the recovery interval guaranteed?1

The recovery interval is not guaranteed in any way—it’s simply a goal....More
blue computer keyboard
Jul 18, 2012

Avoiding logging for user operations1

Why does SQL Server insist on logging all operations, and is it likely that there will be an option to disable logging in future?....More
illustration of key and virtual lock
Jul 04, 2012

Locking and DBCC CHECKDB

From SQL Server 2000 onwards, DBCC CHECKDB runs online by default. Even in SQL Server 2000 though, DBCC CHECKDB still took Schema-Stability locks on....More
Geese running
Jun 27, 2012

Filtering out benign waits

The simple answer is that not all waits need to be analyzed when doing performance troubleshooting....More
multicolored ethernet network cables
Jun 20, 2012

Altering execution priority using Resource Governor

Most people know that Resource Governor allows you to specify CPU and memory limits when contention for these resources occurs, but it’s a little-....More
Beware wooden sign
Jun 19, 2012

Beware of trying to upgrade a database with a read-only filegroup1

Upgrade does not work with read-only filegroups. If you try to take a SQL Server 2008 R2 database with a read-only filegroup and attach it to SQL....More
blue computer keyboard Delete key
Jun 14, 2012

How record DELETEs can cause index fragmentation2

Record deletion can indeed cause fragmentation. There are two kinds of fragmentation described by SQL Server Books Online: logical fragmentation and....More
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Jun 08, 2012

Why do TRUNCATE and DROP TABLE complete so fast?1

In SQL Server 2000 SP3 the deferred drop mechanism was introduced. This works by unhooking the allocations for a table and placing them on the....More
Data word and numbers
May 29, 2012

Do log records ever move in the transaction log?1

Why is it that sometimes when I try to shrink a transaction log file, the shrink fails? Why can’t SQL Server just move log records to the start of....More
May 23, 2012


From SQL Server 2005 onwards (when the metadata subsystem inside SQL Server was extensively rewritten), the database management portion of the....More
May 16, 2012

Curious Case of the missing SOS_SCHEDULER_YIELD waits1

Many of the monitoring scripts/tools for looking at wait statistics aggregate all the wait statistics and return the top 95% of all waits occurring,....More
May 09, 2012

Physical ordering of records in an index

Learn how how Microsoft SQL Server maintains the ordering of record storage in indexes including at what point the records get moved around on the....More
Apr 26, 2012

Is my master database really corrupt?1

It’s becoming increasingly common these days for DBAs to want to offload consistency checking of production databases to a secondary server, so that....More
Apr 17, 2012

How to prevent table scans when searching LOB data?2

If a SELECT has the LOB column in the WHERE clause then the query plan will involve a table scan – as you cannot create a nonclustered index over 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.

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