Re: [PERFORM] Slow cursor
Hi, On Wednesday 26 Oct 2011 14:43:08 Cezariusz Marek wrote: > Is there any known problem with slow cursors in PostgreSQL 8.4.5? > > I have a following query, which is slow (on my database it takes 11 seconds > to execute), probably should be rewritten, but it doesn't matter here. The > problem is, that in cursor, each fetch takes much longer (even few > minutes!), while only the first one should be slow. Am I doing something > wrong? Does the problem persist if you play around with cursor_tuple_fraction? Andres -- Sent via pgsql-performance mailing list (pgsql-performance@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-performance
Re: [PERFORM] Slow cursor
Gregg Jaskiewicz wrote: > Do you really need to query the catalogues ? That on its own is not a > good idea if you want something to run fast and frequently. I know, but I've used it just to show the problem with cursors. I have the same problem with other slow queries, which execute within x seconds in psql or pgAdmin, but for loops in functions it takes at least x seconds to fetch each row. So please just imagine, that it's an other slow query. -- Cezariusz Marek mob: +48 608 646 494 http://www.comarch.com/ tel: +48 33 815 0734 -- Sent via pgsql-performance mailing list (pgsql-performance@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-performance
Re: [PERFORM] Slow cursor
Do you really need to query the catalogues ? That on its own is not a good idea if you want something to run fast and frequently. -- GJ -- Sent via pgsql-performance mailing list (pgsql-performance@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-performance
Re: [PERFORM] slow cursor
This is one thing that I always try to avoid, a single INSERT INTO...SELECT ...FROM or single UPDATE is always faster compared to looping the same within a cursor, unless its inevitable. regards, Luckys. On 4/17/06, Sriram Dandapani <[EMAIL PROTECTED]> wrote: Hi I have a cursor that fetches 150K rows and updates or inserts a table with 150K rows. It takes several minutes for the process to complete (about 15 minutes). The select by itself (without cursor) gets all rows in 15 seconds. Is there a way to optimize the cursor to fetch all records and speed up the process. I still need to do the record by record processing
