Nested Loops Operator
SQL Server Join Methods
When you submit a query to SQL Server – before the query is executed – SQL Server tries to optimize the way data is retrieved from the tables and indexes to create an execution plan that is as effective as possible. One of the decisions the optimizer in SQL Server has to make is which of the join methods (if any) to use.
There are three join methods: Nested Loops Join, Hash Join and Merge Join.
They all have their relative strengths and weaknesses, which will be covered in this blog post.