Re: Multiple databases and shared_buffers

On Thu, Feb 18, 2016 at 4:23 AM, Rakesh Kumar <dcruncher4(at)aim(dot)com> wrote:

> It is a business requirement that we store our clients data in separate
> databases. Our sales folks insist it is non negotiable. Our current
> technology does
> support that and also maintain buffer pools for each db independently.
> That's why I brought this up. Personally I don't think this is a serious
> limitation at all.
>
>
>
>
> -----Original Message-----
> From: Melvin Davidson <melvin6925(at)gmail(dot)com>
> To: pgsql-general <pgsql-general(at)postgresql(dot)org>
> Sent: Wed, Feb 17, 2016 9:53 pm
> Subject: Re: [GENERAL] Multiple databases and shared_buffers
>
> I think this begs the question "Why do you think you need to separate the
> shared_buffers"?
> What version of PostgreSQL are you using?
> What is your O/S?
> How many CPU's on your server?
> How much memory?
>
> On Wed, Feb 17, 2016 at 5:21 PM, John R Pierce <pierce(at)hogranch(dot)com>
> wrote:
>
>> On 2/17/2016 6:54 AM, Data Cruncher wrote:
>>
>> We will be creating multiple databases in a cluster (instance). Is there
>> any way to separate shared_buffers for each database? Looks like not since
>> PG does not allow user created shared buffers.
>>
>>
>>
>> you would need to run multiple instances if you feel you need that level
>> of control over shared_buffers.
>>
>>
>> --
>> john r pierce, recycling bits in santa cruz
>>
>>
>
>It is a business requirement that we store our clients data in separate
databases. Our sales folks insist it is non negotiable. Our current
technology does
>support that and also maintain buffer pools for each db independently.

NOTE: It is very important you provide the version of PostgreSQL and O/S
when addressing this mail list. That is so others searching the archives in
the future
can determine it's pertenance.

That being said, It looks to me like you have a misunderstanding about how
PostgreSQL uses shared_buffers. Data is not actually stored in the
shared_buffers.
Please refer to the following url which explains it's usage.

http://leopard.in.ua/2013/09/05/postgresql-sessting-shared-memory

--
*Melvin Davidson*
I reserve the right to fantasize. Whether or not you
wish to share my fantasy is entirely up to you.