2009/10/26 Grzegorz Jaśkiewicz <gryzman@xxxxxxxxx>: > > > On Mon, Oct 26, 2009 at 10:30 AM, silly8888 <silly8888@xxxxxxxxx> wrote: >> >> Suppose that you have a query, say $sql_query, which is very >> complicated and produces many rows. Which of the following is going to >> be faser: >> >> $sql_query OFFSET 3000 LIMIT 12; >> >> or >> >> BEGIN; >> DECLARE cur1 CURSOR FOR $sql_query; >> MOVE 3000 IN cur1; >> FETCH 12 FROM cur1; >> COMMIT; >> >> Naturally, the former cannot be slower than the latter. So my question >> essentially is whether the MOVE operation on a cursor is >> (significantly) slower that a OFFSET on the SELECT. > > > OFFSET/LIMIT. Afaik cursor always fetches everything. OFFSET/LIMIT process same rows as cursor. There could be only one difference. Cursors uses strategy "fast first row", SELECT uses "minimum complete query time". Regards Pavel Stehule > > > -- > GJ > -- Sent via pgsql-general mailing list (pgsql-general@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-general
