Greetings, I'm in the early stages of preparing to upgrade a production 9.2 cluster to 9.3, by testing the beta of 9.3. All of my testing is happening on RHEL6-x86_64 on a dedicated server with 128GB RAM and 2x Intel Xeon E5-2670 CPUs, with all of $PGDATA residing on an 8 disk RAID10 array. Currently, a full pg_basebackup of my data is approaching 800GB in size (uncompressed), so this isn't a tiny, trivial database. I was curious about how much of a performance gain I'd get from upgrading with the new -j option to pg_upgrade, so first I performed the upgrade without it to get a baseline. The command I ran for the upgrade is as follows: time pg_upgrade -v -d /var/lib/pgsql/9.2/data -D /var/lib/pgsql/9.3/data -b /usr/pgsql-9.2/bin -B /usr/pgsql-9.3/bin time reported the following afterward the upgrade had completed successfully: real 24m59.255s user 0m17.069s sys 15m25.153s I then repeated the upgrade (after blowing away $PGDATA, and running initdb again for 9.3), and re-ran pg_upgrade with the same command as above, only with '-j4' appended to the end. Surprisingly, the completion time was less than 30 seconds faster. I repeated a third time with '-j8', and that was about the same completion time as with '-j4'. I guess I could repeat with 'j2', but I'd be surprised if it was dramatically faster when -j4 was only marginally so. It seems like the parallelism of the -j option doesn't seem to be helping much at all, in my case. Is this expected, or is it possible that there's a bug somewhere? Let me know if I can provide any logs from the upgrade. thanks -- Sent via pgsql-admin mailing list (pgsql-admin@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-admin
