Thanks, that looks useful. I'll investigate once I've got the servers upgraded and replication running. Bruno Wolff III wrote: > > On Wed, Jul 13, 2005 at 18:15:12 +0000, > markMLl.pgsql-general@xxxxxxxxxxxxxxx wrote: > > Many thanks Tom. Inconvenient from the point of view of the application > > but still useful information. > > > > The situation is that I've got a query with numerous subselects, each of > > which has to return exactly one row so I was doing a union with a nulled > > record then selecting the most recent: obviously I need to see bona-fide > > data if it's there. > > you can order by datecol is null, datecol desc to get the most recent > non null date. For example: > area=> select day from (select 'today'::date as day union select > 'tomorrow'::date as day union select null as day) as un order by day is null, > day desc; > day > ------------ > 2005-07-16 > 2005-07-15 > > (3 rows) > > ---------------------------(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 -- Mark Morgan Lloyd markMLl .AT. telemetry.co .DOT. uk [Opinions above are the author's, not those of his employers or colleagues] ---------------------------(end of broadcast)--------------------------- TIP 2: Don't 'kill -9' the postmaster
