Hash join

What is a hash join?
msimons4Asked:
Who is Participating?

Improve company productivity with a Business Account.Sign Up

x
 
sdstuberConnect With a Mentor Commented:
This is a high level description

when you hash join two rowsets  each row in each set has a hash value generated for it.
When comparing two rows to see if they match, the hash values are compared, rather than the column values themselves.

This is useful because  the hashing creates a hash table that acts like mailboxes.  To compare two rows, you simply check if they both resolve to the same "address" because they have the same hash value.  This is fast.

The downside is the hash table consumes memory and the generating of hash values takes time.



0
Question has a verified solution.

Are you are experiencing a similar issue? Get a personalized answer when you ask a related question.

Have a better answer? Share it in a comment.

All Courses

From novice to tech pro — start learning today.