Nested Loops, Hash, Or Merge: Which Is Best?

Grant Fritchey dodges the important questions:

First response, also a joke, was the question at the title of this post:

What is the preferred operator when joining tables: Hash Match, Nested Loops or Merge?

While my immediate response to this question is, yes. Meaning, they’re all preferred, situationally. I decided to expand on that a bit.

I completely agree with Grant:  there is no single best operator.  If there were, database companies wouldn’t have multiple options.  That said, in an ideal world, all joins would be merge joins; in our fallen world, nested loops and hash matches often prove superior second-best alternatives.

Related Posts

Wait Stats And Missing Indexes

Arthur Daniels explains that missing indexes can cause high wait stat counts to appear: At first, this statement might sound a bit confusing. Usually, we expect wait statistics to show us what a query is waiting on, whether it’s waiting on memory, loading pages from disk, or any of the other numerous wait types.Once you […]

Read More

Monitoring Entity Framework

Grant Fritchey loves Entity Framework: Yes, Entity Framework will improve your job quality and reduce stress in your life. With one caveat, it gets used correctly. That’s the hard part right? There is tons of technology that makes things better, if used correctly. There are all sorts of programs that make your life easier, if […]

Read More

Categories

July 2018
MTWTFSS
« Jun Aug »
 1
2345678
9101112131415
16171819202122
23242526272829
3031