Hash Join require Full Table Scan

Posted by Pedro Magalhaes on Stack Overflow See other posts from Stack Overflow or by Pedro Magalhaes
Published on 2010-04-09T02:20:15Z Indexed on 2010/04/09 2:23 UTC
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joins

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So, I want to know if to make a Hash Join between two tables is necessary to make a full table scan on the collumns?

If i want to join COL1 wiht COL2, and COL1 is smaller, the It makes a full scan in COL1 creating a Hashmap then makes a full scan in COL2 using the sabe hash function.

Is this correct?

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