May 2012 - Posts

• Parallel Execution Plans Suck

  Summary: A deep dive into SQL Server parallelism, and a potential performance problem with parallel plans that use TOP. There was an interesting question asked by Mark Storey-Smith on dba.stackexchange.com back in October 2011.  He was looking at Read More... Posted Thursday, May 03, 2012 7:57 AM by Paul White | 8 Comments Filed under: Internals, Top, Query Plans, Parallelism, Performance

• Query Optimizer Deep Dive - Part 4

  This is the final part in a series of posts based on the content of the Query Optimizer Deep Dive presentations I have given over the last month or so at the Auckland SQL Users’ Group and the SQL Saturday events in Wellington, New Zealand and Adelaide, Read More... Posted Tuesday, May 01, 2012 3:36 AM by Paul White | 7 Comments Filed under: Query Optimizer, Internals, Undocumented, Costing, Trace Flags Attachment(s): Deep Dive.zip