Обсуждение: Maximum number of concurrent users

Hi

We are using PostgreSQL 8.3.1 version under windows.
We want to know whether there is any limit on Maximum number of
concurrent users.
In specific, can Postgres handle 1000 concurrent queries?
Regarding our Data size,

We have 40 tables and in total we have 2GB data.
We are using normal Pentium Quad core processor, 3GHZ system with 2GB
RAM as Database Server.

Kindly provide your inputs.

Thanks in advance
S.Kesavan
Emmeskay Systems,
Chennai, India.

>>> Kesavan <kesavan@emmeskay.com> wrote:

> In specific, can Postgres handle 1000 concurrent queries?

It can.

> We are using normal Pentium Quad core processor, 3GHZ system with 2GB

> RAM as Database Server.

With four processors, depending on your drive array configuration, you
are likely to get better performance funneling the requests through a
connection pool of about 8 to 16 connections.  (With a lot of
spindles, maybe more.)

-Kevin

On Mon, Aug 4, 2008 at 9:49 AM, Kesavan <kesavan@emmeskay.com> wrote:
> Hi
>
> We are using PostgreSQL 8.3.1 version under windows.
> We want to know whether there is any limit on Maximum number of concurrent
> users.
> In specific, can Postgres handle 1000 concurrent queries?

Sure.  Give it enough hardware, and it can handle 1,000 concurrent
select field from table where pkey = 2345 type queries pretty well.  I
wouldn't try to run 1,000 reporting queries hitting four tables with
1B to 1G to 1Tera rows or anything.

> Regarding our Data size,
>
> We have 40 tables and in total we have 2GB data.
> We are using normal Pentium Quad core processor, 3GHZ system with 2GB RAM as
> Database Server.

Well, since we have no idea what your usage pattern will be, this
question is a little bit like "how many angels can dance on the head
of a pin?"  i would put more memory in your server so it can fit in
memory easily.  4Gig should be enough.  8Gig would be more than
enough.  But if you're running transactions. you're gonna have to tell
us what kind of drive subsystem you have, cause one drive won't handle
it.

Note that in transactional work, number of drives and their
configuration are probably more important than anything else.

Hi!

I have no experience running postgreSQL under windows but when reading
the Windows FAQ (http://www.postgresql.org/docs/faqs.FAQ_windows.html#4.4
)
Its seem like you can get in trouble with some of the libraries that
postgres uses.

Regarding performance it's hard to tell because of all the different
factors like raid type/disk count/type of queries/indexes etc. etc.

But it sounds like the machine is to weak to handle 1000 concurrent
queries.

Best regards,
Mathias Stjernstrom
_____________________________________
Weblog at http://www.stjernstrom.se/


On 4 aug 2008, at 17.49, Kesavan wrote:

> Hi
>
> We are using PostgreSQL 8.3.1 version under windows.
> We want to know whether there is any limit on Maximum number of
> concurrent users.
> In specific, can Postgres handle 1000 concurrent queries?
> Regarding our Data size,
>
> We have 40 tables and in total we have 2GB data.
> We are using normal Pentium Quad core processor, 3GHZ system with
> 2GB RAM as Database Server.
>
> Kindly provide your inputs.
>
> Thanks in advance
> S.Kesavan
> Emmeskay Systems,
> Chennai, India.
>
> --
> Sent via pgsql-admin mailing list (pgsql-admin@postgresql.org)
> To make changes to your subscription:
> http://www.postgresql.org/mailpref/pgsql-admin

On Mon, Aug 4, 2008 at 11:51 AM, Mathias Stjernström
<mathias@globalinn.com> wrote:
> Hi!
>
> I have no experience running postgreSQL under windows but when reading the
> Windows FAQ (http://www.postgresql.org/docs/faqs.FAQ_windows.html#4.4)
> Its seem like you can get in trouble with some of the libraries that
> postgres uses.
>
> Regarding performance it's hard to tell because of all the different factors
> like raid type/disk count/type of queries/indexes etc. etc.
>
> But it sounds like the machine is to weak to handle 1000 concurrent queries.

Oh my, I missed the windows part.  If you need to handle 1000
concurrent queries, I can't think of any db I'd want to use on windows
to do that.  Even Oracle would advise you to run on some flavor of
unix.  Maybe MSSQL server can handle it.

OTOH, 20 to 100 spindles on an 8 to 16 CPU machine might be able to
keep up if the queries are small enough and you use query pooling.

"Scott Marlowe" wrote:

>On Mon, Aug 4, 2008 at 11:51 AM, Mathias Stjernström
><mathias@globalinn.com> wrote:
>> Hi!
>>
>> I have no experience running postgreSQL under windows but when reading the
>> Windows FAQ (http://www.postgresql.org/docs/faqs.FAQ_windows.html#4.4)
>> Its seem like you can get in trouble with some of the libraries that
>> postgres uses.
>>
>> Regarding performance it's hard to tell because of all the different factors
>> like raid type/disk count/type of queries/indexes etc. etc.
>>
>> But it sounds like the machine is to weak to handle 1000 concurrent queries.
>
>Oh my, I missed the windows part.  If you need to handle 1000
>concurrent queries, I can't think of any db I'd want to use on windows
>to do that.  Even Oracle would advise you to run on some flavor of
>unix.  Maybe MSSQL server can handle it.

Postgres cannot handle that on windows. See

<http://wiki.postgresql.org/wiki/Running_%26_Installing_PostgreSQL_On_Native_Windows#I_cannot_run_with_more_than_about_125_connections_at_once.2C_despite_having_capable_hardware>

Rainer