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Having some difficulty with a MERGE operation.  We keep getting the following error, but cannot see why:
Failed [5758 : HY000] The search condition must fully specify the Target table primary index and partition column(s) and expression must match INSERT specification primary index and partition column(s).

Hello all,
I would like to point out what I think is a bug and solicit ideas for a way to make this work.
I have a stage table and I want to merge it into a table with a surrogate key.  I want auto-generate the surrogate key on insert and I only want to update records that need updating.