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Posted by Ami Levin on Wednesday, 21 December 2011

Writing a query that joins several tables is easy, right? There are just a few major join types and their syntax is pretty straightforward and clear. So how come such a simple join be the source of so many headaches? Why does one query with a simple JOIN take forever and another, similar one a fraction of a second? If you’ve ever wondered what goes on under the covers and how SQL Server implements your joins, this article will help you get started.