2008/10/12 Grzegorz Jaskiewicz <[EMAIL PROTECTED]>: > so I wonder, quite few times ppl asked me about my-word database TOP % > PERCENT (and I guess ms-word db has it too). > Now that postgres has limit(subselect) - postgresql can do the same thing. > But, using a count(*) in subselects isn't very efficient. The backend gets > information from limit X, so I figure it shouldn't be a very big deal to add > LIMIT %d PERCENT , and pass it on as percentage, instead of just number of > rows. > I can give it a go and try to implement it myself, but wanted to ask here > first for opinion on syntax (I have no idea what would be right syntax by > sql standards), and how keen would you guys be on accepting such patch. > > thanks. > >
I'm afraid you will not succeed it because PostgreSQL doesn't know how many rows are totally returned until it returns the last row, which is as ineficient as count(*) as you point out. Regards, -- Hitoshi Harada -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
