Hi Jason,

a quick question, because I'm just not getting it straight in my head.

You said "For any joins, use the first (top) input to build the hash table and the second (bottom) input to probe the hash table"

Kimberly Tripp said [SQLSkills IE1, module 10 Indexing strategies, Slide 37, Join Strategies]

"Hash join

Two-phase operation (build, then probe): Build table(smaller set) and probe table (larger set) allowing SQL to join extremely large sets - in MEMORY (can spill)"

If you are both correct, which is a distinct possibility, that would indicate that you are talking about different things.

When you say 'first(top) input', do you mean the first table the from clause, or the ordering in the plan post optimisation, or something else ?

Can you help me to clear up my confusion between the differences [in my understanding] between your article and Kimberly's course?

Thanks

Simon