NikhilS <[EMAIL PROTECTED]> writes: > To allow both of the above to hold, I think the subselect will have to be > treated like a EXPR_SUBLINK subquery. I was wondering if we have a similar > mechanism for plain selects/subselects to check and restrict their output to > a single row.
No. Offhand I think you'd either need to relax EXPR_SUBLINK to allow multiple output columns, or invent a ROW_SUBLINK SubLinkType that is just like EXPR_SUBLINK except for allowing multiple output columns. The latter would probably be less likely to break other things... regards, tom lane ---------------------------(end of broadcast)--------------------------- TIP 9: In versions below 8.0, the planner will ignore your desire to choose an index scan if your joining column's datatypes do not match