SQLOS’s DMVs Continue

sys.dm_os_schedulers Q. Do I need to by more CPUs? In order to answer this question you have to find out if your load is really CPU bounded.  Your load is really CPU bounded if a number of runnable tasks per each scheduler always greater than 1 and all of your queries have correct plan.  The…



SQL Server 2005 has a large number of DMVs that you can take advantage of especially when you try to understand behavioral characteristics of your SQL Server 2005 installation. DMVs expose enormous amount of information but how can you make use of it? What questions you can answer using DMVs?    So in order to…


Set of new features in SQL Server 2005 enabled by SQLOS

Couple of weeks ago I had a chance to visit set of our customers and talk to them directly. It was an unforgettable experience. As a part of the visit I made set of presentations related to SQLOS and new features it enables in SQL Server 2005. I thought that some of you might be…


Retrieving information about CPUs’ relationships

In order for server side applications to run efficiently on modern hardware they have to understand hardware layout. As we are moving towards multicore and multi node NUMA systems, understanding relationships amongst cores, logical and physical CPU has become very important.  Before we jump into how applications can do it, we need to define what…


Q and A: Clock Hands – what are they for?

Q1 I read in your blog about the new algorithm with two clock hands to control memory consumption, but I really would like to understand exactly what the hands are doing and if they relate to the lazywriter. A1. In SQL Server 2005 we have separated database cache, Buffer Pool, and the rest of the…


Talking Points around Memory Manager in SQL Server 2005

Yesterday I gave a talk around SQL Server 2005’s memory manager. The talk was rather chalk talk. It included memory manager changes in SQL 2005 as well as changes post CTP15. For the talk I prepared several slides – basically talking points that I thought might be interesting to everyone.  If you were following my blog you will notice that slides below closely…


SQL Server 2005 NUMA support & troubleshooting

SQL Server 2005 has been designed to take advantage of NUMA features exposed by both hardware and the Windows operating system. There are several caveats that you need to be aware when attempting to run SQL Server on NUMA platforms.   In this post I would like to go over both Windows’s and SQL Server’s…


SQLOS helps SQL Server to leverage hardware capabilities

I just finished an article on how SQLOS helps SQL Server to leverage hardware capabilities http://blogs.msdn.com/slavao/articles/441058.aspx.  It will be interesting to hear your comments, thoughts. Thanks a lot in advance


SQLOS Caching

  Yukon caching vs SQL2000 What makes Yukon memory management different from SQL2000 is elaborative caching framework.  In SQL2000 there are two major caches: data page cache, called Buffer Pool and procedure cache, cache of query plans. Buffer Pool and procedure cache are very tightly coupled. For example procedure cache relies on buffer pool’s eviction…


Be aware: FLS-Fiber Local Storage

Problem: In the last several months there were several publications describing usage of fibers.  When covering SQLOS’s scheduling I will go into more details about them. Today I would like to touch on the subject on how to make your dlls/libraries more robust in the fiber environment.   As you know, when running SQL server…