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• Internals
• Joins
• Partitioning
• Performance
• Undocumented

• Why Doesn’t Partition Elimination Work?

  Given a partitioned table and a simple SELECT query that compares the partitioning column to a single literal value, why does SQL Server read all the partitions when it seems obvious that only one partition needs to be examined? Sample Data The following Read More... Posted Wednesday, September 12, 2012 10:52 AM by Paul White | 20 Comments Filed under: Query Plans, Performance, Conversions, Partitioning

• Join Performance, Implicit Conversions, and Residuals

  You probably already know that it’s important to be aware of data types when writing queries, and that implicit conversions between types can lead to poor query performance.  Some people have gone so far as to write scripts to search the plan cache Read More... Posted Tuesday, July 19, 2011 1:17 AM by Paul White | 17 Comments Filed under: Internals, Query Plans, Undocumented, Performance, Joins, Conversions