The Impact of Non-Updating Updates

re: The Impact of Non-Updating Updates

Andy Warren — Sat, 14 Aug 2010 13:36:48 GMT

Great post Paul, good to see it run through all the scenarios.

re: The Impact of Non-Updating Updates

Paul White — Sat, 14 Aug 2010 14:48:48 GMT

Thanks Andy!

re: The Impact of Non-Updating Updates

Marc Brooks — Tue, 07 Sep 2010 23:18:11 GMT

Another things that is often overlooked when doing non-changing of columns is that the referential integrity will checked even when the value is not changed. This means that

UPDATE dbo.Child SET SomeColumn=@something WHERE ChildID=@someKey

is going to be faster than

UPDATE dbo.Child SET SomeColumn=@something, ParentID=@someParentKey WHERE ChildID=@someKey

EVEN if the @someParentKey is the same value as what is currently in the row.

Read Committed, Shared Locks, and Rollbacks

Paul White: Page Free Space — Sun, 31 Oct 2010 16:19:44 GMT

In this post I cover a little-known locking optimization that provides a surprising answer to the question:

Beware Sneaky Reads with Unique Indexes

Paul White: Page Free Space — Mon, 13 Dec 2010 15:34:17 GMT

A few days ago, Sandra Mueller ( twitter | blog ) asked a question using twitter’s #sqlhelp hash tag: