Thread: pgsql: Don't try to optimize EXISTS subqueries with empty FROM-lists: we

Log Message:
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Don't try to optimize EXISTS subqueries with empty FROM-lists: we need to
form a join and that case doesn't have anything to join to.  (We could
probably make it work if we didn't pull up the subquery, but it seems to
me that the case isn't worth extra code.)  Per report from Greg Stark.

Modified Files:
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    pgsql/src/backend/optimizer/plan:
        subselect.c (r1.142 -> r1.143)
        (http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/backend/optimizer/plan/subselect.c?r1=1.142&r2=1.143)