Disabling Nested Loop Join Optimization

Dmitry Pilugin explains the differences between trace flag 2340 and the DISABLE_OPTIMIZED_NESTED_LOOP query hint:

This optimization provides a great boost with a sufficient number of rows. You can read more about its test results in the blog OPTIMIZED Nested Loops Joins, created by Craig Freedman, an optimizer developer.

However, if the actual number of rows is less than the expected one, then CPU additional costs to build this sort may hide its benefits, increase CPU consumption and reduce its performance.

Read the whole thing.  I think the likelihood of using either this hint or the trace flag is near nil, but crazy things do come up.

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