The SQL Server Wait Type Repository…
As part of my talk at the 2009 US PASS Summit here in Seattle called Inside SQL Server Wait Types, I’m creating this blog post as a reference point that can be used to find out information about wait types in SQL Server 2005 and 2008. My hope is that if you have a question about a wait type you encounter with SQL Server 2005, 2008, or beyond, you will use this blog post as the starting point. This blog post should also be used as an enhancement to what you can find at the following SQL Server Books Online topic:
sys.dm_os_wait_stats (Transact-SQL)
Why use this blog post over other references? Because information in this blog post will be based on the the actual product source code and empirical testing of scenarios that cause these wait types.
This page is under construction but will contain the following types of information:
1) Table of all wait types as listed in sys.dm_os_wait_stats.
This table will contain the following types of information:
- types organized by categories
- Which types apply to SQL 2005, SQL 2008, or both
- More descriptions for how you might encounter these
- Tips on what to do (if anything)
- List of specific types that can be safely ignored
2) Links to details on some wait types
Some of these types deserve special treatment so we will provide links to more detailed scenarios for certain types including other blog posts, posts on this blog, whitepapers, etc
This include more details on how you can use various tools to see waits such as DMVs, Extended Events, Management Data Warehouse, Activity Monitor, and Performance Counters.
3) Other References on the topic
I want this blog post to be a living document and help feed enhancements to the SQL Server Books Online. So if you encounter a question on a wait type that is confusing or not listed in this post, please post a comment to this blog post or email psssql@microsoft.com. This isn’t to obtain “free support” for a problem but to be used to help enhance and create the right content for the community on this topic.
Look for the expansion of this blog post with these details in the next 3-4 weeks following the PASS conference.
Bob Ward
Microsoft
