SQLCAT.Com – eBook Downloads

As of September 1, 2013 we decided to remove SQLCAT.COM site and use MSDN as the primary vehicle to post new SQL Server content. This was done to minimize reader confusion and to streamline content publication.  MSDN SQLCAT blogs already includes most SQLCAT.COM Content and will continue to be updated with more SQLCAT learnings.  You can also… Read more

SQLCAT.com consolidated index of Whitepapers

In an effort to migrate as much content as possible from SQLCAT.com to the MSDN SQL CAT site we have consolidated all of the Whitepapers published over the last few years.   While all of the content actually exists on Technet and MSDN download sites, SQLCAT was a great resource to start looking.  Hopefully this will… Read more

Concurrency Series: Minimizing blocking between updaters

  Author: Sunil AgarwalReviewers: Kun Cheng, Chuck Heinzelman, Shaun Tinline-Jones, Sanjay Mishra, And Kevin Liu When a transaction T1 modifies a row, it takes an X lock on the row for the duration of the transaction. If another concurrent transaction T2 wants to modify the same row, it gets blocked waiting for T1 to complete…. Read more

Concurrency Series: Why do I get blocked when no one has locked the row(s) being queried?

 Author: Sunil AgarwalReviewers: Kun Cheng, Chuck Heinzelman, Shaun Tinline-Jones, Sanjay Mishra, Kevin Liu Recently I was working with a customer who was surprised to see blocking when accessing a data row which was not locked?  Let me describe the scenario using an example. Example: — create a simple table for our examples create table basic_locking… Read more

Concurrency Series: Basics of Transaction Isolation Levels

Author: Sunil AgarwalReviewers: Kun Cheng, Chuck Heinzelman, Shaun Tinline-Jones, Sanjay Mishra, Kevin Liu In this series of blogs, I want to show some common concurrency questions that we get asked by customers. Before we look into common concurrency issues seen by customers, it will be good to review the transaction isolation levels provided in SQL… Read more