Re: 9.1 vs 8.4 performance

On Mon, Sep 24, 2012 at 5:47 AM, salah jubeh <s_jubeh(at)yahoo(dot)com> wrote:
> Hello Guys,
>
> Thanks for reply, and sorry for late response. Here is more details.
>
> 1. Both servers are installed on parallel on the same machine, so there is
> no difference in Hardware.
> 2. Both servers have the same configuration setting except the ports (5432
> and 5433).
> 3. I have run VACUUM ANALYSE command on both databases and no change in
> performance for both of them.
> 4. The execution plans are certainly different, I tried to use diff and the
> graphical representation pg-admin but the execution plan is a around 1700
> lines, this is why I did not post them.
>
> I have noticed that, the filter location varies whe run the same queries
> using the two servers. In 8.4 the execution plan is mostly filter then join.
> In 9.1 join and then filter. But this is just a rough overview.
>
> Regards
>
>
>
> ________________________________
> From: "Gauthier, Dave" <dave(dot)gauthier(at)intel(dot)com>
> To: Scott Marlowe <scott(dot)marlowe(at)gmail(dot)com>; salah jubeh <s_jubeh(at)yahoo(dot)com>
> Cc: pgsql <pgsql-general(at)postgresql(dot)org>
> Sent: Friday, September 21, 2012 9:40 PM
>
> Subject: Re: [GENERAL] 9.1 vs 8.4 performance
>
> One thing I sometimes forget to do after loading up an empty DB with data is
> to run "analyze". I usually "remember" once I see poor query performance,
> run the analyze, and its fixed.
>
> -----Original Message-----
> From: pgsql-general-owner(at)postgresql(dot)org
> [mailto:pgsql-general-owner(at)postgresql(dot)org] On Behalf Of Scott Marlowe
> Sent: Friday, September 21, 2012 3:01 PM
> To: salah jubeh
> Cc: pgsql
> Subject: Re: [GENERAL] 9.1 vs 8.4 performance
>
> On Fri, Sep 21, 2012 at 8:32 AM, salah jubeh <s_jubeh(at)yahoo(dot)com> wrote:
>> Hello,
>>
>> I have two postgresql servers 9.1.5 and 8.4.8 running on ubuntu
>> machine, both are fresh installs and both has the same configuration
>> files and databases.
>>
>> I am running queries sequentially on each machine using a database
>> dumped from a life server , and 9.1 server is much slower than 8.4.
>
> So how different or similar are these two machines?

We need to see the plans.

merlin