Francesc Leveque <webmaster(at)loroadictos(dot)com> writes:
> Is correct to do something like?:
> SELECT row1,row2 FROM mytable
> WHERE (row1,row3) IN
> (SELECT row1 as p1,MAX(row3) as p2 FROM mytable
> WHERE row3 <= current_date
> GROUP BY row1)
Sure.
> I mean, I don't see documentation about subselects returning more than
> one column, but it seems to work...
http://www.postgresql.org/docs/7.4/static/functions-subquery.html#AEN12497
regards, tom lane