December 2012 - SQLPerformance.com

Should I use NOT IN, OUTER APPLY, LEFT OUTER JOIN, EXCEPT, or NOT EXISTS?

SQL Sentry's Aaron Bertrand (@AaronBertrand) digs into the left anti semi join, comparing NOT IN, NOT EXISTS, OUTER APPLY, EXCEPT, and OUTER JOIN methods.

Aaron Bertrand ◆ December 27, 2012

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Trimming the Transaction Log Fat

In many SQL Server workloads, especially OLTP, the database’s transaction log can be a bottleneck that adds to the time it takes a transaction to complete. Most people assume that the I/O subsystem is the real bottleneck, with it not being able to keep up with the amount of transaction log being generated by the workload.

Paul Randal ◆ December 17, 2012

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SQL Server 2012 Service Pack 1 & Cumulative Update 1

Recently, Microsoft pushed out Service Pack 1 for SQL Server 2012, and they quickly followed up with Cumulative Update 1 for Service Pack 1. The reason for this is that the service pack – due to longer development and regression testing cycles – did not contain any of the fixes from RTM Cumulative Updates 3 & 4. Since many people have waited – based on mostly speculative bias at this point – to even start testing SQL Server 2012 until Service Pack 1 was released, I thought it might be useful to cover a couple of the scenarios you might come across.

Aaron Bertrand ◆ December 12, 2012

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TRANSACTION_MUTEX and Multi-Session Transaction Access

I recently encountered high TRANSACTION_MUTEX accumulated wait time on a client system. I couldn’t recall a case where I saw this wait type as near the top of the “high waits” list and I was curious about what factors could push this type of overall wait time.

The Books Online definition of TRANSACTION_MUTEX is that it "occurs during synchronization of access to a transaction by multiple batches." Not many areas within the SQL Server engine expose this type of functionality, so my investigation was narrowed down to the following technologies:

Joe Sack ◆ December 10, 2012

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