On Tue, May 12, 2009 at 08:06:25PM +0800, Ow Mun Heng wrote: > From: pgsql-general-owner@xxxxxxxxxxxxxx [mailto:pgsql-general- > On Tue, May 12, 2009 at 01:23:14PM +0800, Ow Mun Heng wrote: > >Not sure why this is better than using separate columns though. Maybe a > >new datatype and a custom aggregate would be easier to work with? > > The issue here is the # of columns needed to populate the table. > > The table I'm summarizing has close to between 50 to 100+ columns, if the > 1:5x is used as a yardstick, then the table will get awfully wide quickly. > > I need to know how to do it first, then test accordingly for performance and > corner cases. Yes, those are going to be pretty wide tables! Maybe if you can make the source tables a bit "narrower" it will help things; PG has to read entire rows from the table, so if your queries are only touching a few columns then it's going to need a lot more disk bandwidth to get a specific number of rows back from the table. -- Sam http://samason.me.uk/ -- Sent via pgsql-general mailing list (pgsql-general@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-general
