Hash Match

The Hash Match physical operator builds a hash table by computing a hash value for each row from its build input. A HASH:() predicate with a list of columns used to create a hash value appears in the Argument column. Then, for each probe row (as applicable), it computes a hash value (using the same hash function) and looks in the hash table for matches. If a residual predicate is present (identified by RESIDUAL:() in the Argument column), that predicate must also be satisfied for rows to be considered a match. Behavior is slightly different based on the logical operation being performed:

See Also
Distinct Understanding Hash Joins
Hash Match Team Union

  


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