Re: Perf decreased although server is better

How did you migrate from one system to the other?

[ I recently moved a large time series table from 9.5.4 to 9.6.1 using dump
and restore. Although it put the BRIN index on the time column back on, it
was borked. Reindexing didn't help. I had to switch it to a regular btree
index. I think the data wasn't inserted back into the database in time
order. Therefore, because it was all over the place, the efficiency gains
from the BRIN index were lost. It was probably because I restored it with
"-j 8". -- It is possible something you didn't expect when moving
introduce new inefficiencies. I also found running pg_repack after the
restore helped performance (and storage size) on my new system too. ]

Do you have all of the kernel settings configured per best practices?
Sometimes it is easy to forget them when you get totally focused on just
moving the data.
(Things such as your hugepages settings)

With 9.6 you can enable parallel queries. Of course you wouldn't be
comparing apples-to-apples then, but take advantage of that feature if you
can.

On Wed, Nov 2, 2016 at 9:26 AM, Benjamin Toueg <btoueg(at)gmail(dot)com> wrote:

> Hi everyone,
>
> I'm facing a peformance decrease after switching to a more performant VPS
> : http://serverfault.com/questions/812702/posgres-perf-
> decreased-although-server-is-better
>
> My questions are:
>
> 1. What benchmark should I perform before switching to a new server?
> 2. What's your rule of thumb regarding my specific issue? What should
> be investigated first?
>
>
> Best Regards,
>
> Benjamin
>
>