Re: [HACKERS] Parser bug?

Bruce Momjian wrote: >> I think this is a bug in 6.4: >>  >> bray=> select rcname, rcsrc from pg_relcheck where rcrelid
=>> '115404'::oid and rcrelid in (select min(rcrelid) from pg_relcheck >> group by rcname); ERROR:  parser: Subselect
hastoo many or too >> few fields. >>  >> The subselect only produces one column; so I think that the >> error message
iswrong. > >What is the GROUP BY doing?
 

This relates to the bug in pg_dump which messes up inherited constraints.

The object is to find which is the table in an inheritance hierarchy for
which the check constraint is first defined, which must inevitably be the
one with the lowest numbered oid.  The GROUP BY operates with the aggregate
to return the low-numbered oid for each separate rcname.

-- 
Oliver Elphick                                Oliver.Elphick@lfix.co.uk
Isle of Wight                              http://www.lfix.co.uk/oliver              PGP key from public servers; key
ID32B8FAA1                ========================================    "The LORD is nigh unto all them that call upon
him,to     all that call upon him in truth."                                          Psalms 145:18