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A copy of my content from SQLBlog.com plus occasional new content.
Showing posts with label Partitioning. Show all posts
Showing posts with label Partitioning. Show all posts

Monday, 17 June 2013

Improving Partitioned Table Join Performance

Improving Partitioned Table Join Performance

The query optimizer does not always choose an optimal strategy when joining partitioned tables. This post looks at an example of that, showing how a manual rewrite of the query can almost double performance, while reducing the memory grant to almost nothing.

Wednesday, 12 September 2012

Why Doesn’t Partition Elimination Work?

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?