• @Jon

    That's an interesting thought. Thanks for that. I must confess that I've never come across this happening. Would anything go wrong if that table that had a clustered index that wasn't the primary key and didn't even have a unique constraint and that was never used then became a heap? Wouldn't people want to know that a table had such an unusual choice for a clustered index that was unused even thought the table was being updated? I'll check that with my editor, who knows a lot more about that than I.

    Best wishes,
    Phil Factor