Collapse Showplan Operator
The Collapse operator optimizes update processing. When an update is performed, it can be split (using the Split operator) into a delete and an insert. The Argument column contains a GROUP BY:() clause that specifies a list of key columns. If the query processor encounters adjacent rows that delete and insert the same key values, it replaces these separate operations with a single more efficient update operation.
Collapse is a logical and physical operator.
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Graphical execution plan icon