On 01/03/14 14:42, Tory M Blue wrote:
> 
> 
> 
> On Fri, Jan 3, 2014 at 11:33 AM, Jan Wieck <JanWieck at yahoo.com
> <mailto:JanWieck at yahoo.com>> wrote:
> 
>     On 01/02/14 16:12, Tory M Blue wrote:
>     > We are getting outside of slon and into postgres and i'll try to keep
>     > this light, here are my postgresql custom config aspects
> 
>     Postgres and its architecture very much affect the behavior and
>     performance of Slony. I'm afraid that they cannot be viewed completely
>     isolate from each other.
> 
>     > The hardware is being refreshed but right now it's an 8 core, 32GB
>     > CentOS system, being replaced with some pretty big hardware
>     > 256GB/32cores many SSD's. But tuning this now and knowing where I need
>     > to tweak when I add the added capacity would be great.
> 
>     The slon process uses one single database connection to the data
>     provider for the copy operation and another single database connection
>     to feed the data into the new replica. A single Postgres session only
>     utilizes one single core. It therefore makes zero difference if you are
>     upgrading from a dual core to 64 cores or more.
> 
>     The suggestions made about work mem and maintenance work mem are valid.
>     If you are using a dedicated DB user for all your slon database
>     connections you can tweak these per server via ALTER USER.
> 
> 
>     Regards,
>     Jan
> 
> 
> 
> Okay that is interesting.. "If you are using a dedicated DB user for all
> your slon database connections, you can tweak these per server via Alter
> User", what will that do for me? We do use the same user across the
> board and i figured I would just modify my postgresql.conf. So i'm a tad
> confused :)

Assuming you have a user "slon" and all your slon processes use that DB
user to do their work. You connect with psql to a Postgres server as a
superuser ("postgres" for example) and issue the command

    ALTER USER slon SET work_mem TO "2048MB";