CTE (Common Table Expression) vs Temp tables or Table variables, which is faster?

Question

CTE (Common Table Expression) vs Temp tables or Table variables, which is faster?

Answer 1

As I already said in my comment: IT DEPENDS!

It really does depend on your query, your data (how much is there? What kind is it??) and much more.

A few bullet points to remember, though:

• a CTE is an "inline view" valid only for the next statement; if possible, SQL Server will keep a temporary result in memory

• Temp Tables come in two flavours: those visible to your connection only (create table #temp), or those that are globally visible to all connections (create table ##temp); both will be auto-dropped when no connection is using them anymore. You can define indices on temp tables, and they're part of transactions

• Table variables don't allow you to create indices on them, nor do they participate in the transactional dance - this can be a pro or a con - just be aware of it! A ROLLBACK has no effect on the data contained in a table variable....