I have an UPDATE statement that joins two table by SendId. One table, I'll call it T1, has a clustered index on SendId ASC. The other table I will call T2 also has a clustered index on SendID ASC. All the columns from T2 are used to update T1. The execution plan shows a Clustered index scan on T2 and a Clustered Index Seek on T1 going into a Nested Loops inner join. Immediately following is a Distinct Sort that is done on SendId ASC. Why the Distinct SORT if the tables are already ordered by SendID?
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