On 12/02/2016 09:40 AM, Tom DalPozzo wrote:
Hi, I've two tables, t1 and t2, both with one bigint id indexed field and one 256 char data field; t1 has always got 10000 row, while t2 is increasing as explained in the following. My pqlib client countinously updates one row in t1 (every time targeting a different row) and inserts a new row in t2. All this in blocks of 1000 update-insert per commit, in order to get better performance. Wal_method is fsync, fsync is on, attached my conf file. I've a 3.8ghz laptop with evo SSD. Performance is measured every two executed blocks and related to these blocks. Over the first few minutes performance is around 10Krow/s then it slowly drops, over next few minutes to 4Krow/s, then it slowly returns high and so on, like a wave. I don't understand this behaviour. Is it normal? What does it depend on?
Have you looked at the Postgres log entries that cover these episodes? Is there anything of interest there?
Also, when I stop the client I see the SSD light still heavily working. It would last quite a while unless I stop the postgresql server, in this case it suddenly stops. If I restart the server it remains off. I'm wondering if it's normal. I'd like to be sure that my data are safe once commited. Regards Pupillo P.S.: I put this question in general questions as my concern is not if the performance is high or not.
-- Adrian Klaver adrian.klaver@xxxxxxxxxxx -- Sent via pgsql-general mailing list (pgsql-general@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-general
