Обсуждение: PostgreSQL on the internet

Bob Pawley wrote:
> Hi
>
> I am kicking around the idea of using PostgreSQL as a web based
> service. Access to the site will be through a separate
> application/interface.

Why web-based if you're installing an application to the user's PC.

> Can someone tell me what criteria I need to look at in order to
> determine how many clients can be using the website, each with their
> own database, at one time??

How big is each database, and what will the users be doing with them?

--
   Richard Huxton
   Archonet Ltd

On Dec 3, 2007 9:33 AM, Bob Pawley <rjpawley@shaw.ca> wrote:
>
> Hi
>
> I am kicking around the idea of using PostgreSQL as a web based service.
> Access to the site will be through a separate application/interface.
>
> The user's interface will install the database on entry to the website. When
> the user exits the site, the database will be dumped to the user's computer
> and eliminated from the website. It seems to me that it is possible to make
> this dump and restore invisible, or mostly invisible,  to the user.

You mean, I suppose, that you'll create a db on your server for the
user, and load schema / data into that?  Then dump it out to the user
when they're ready to go, and drop the db on your end?

Seems pretty easily doable to me.

> Can someone tell me what criteria I need to look at in order to determine
> how many clients can be using the website, each with their own database, at
> one time??

How much memory your db server has, how big the db will be, what kind
of load it will have, how the db is tuned, etc...  I'd try it out
after building a simple test case db and see how the system behaves
with say 1, 2, 4, 10, 20 etc users.  Get a feel for it.

I think a bit more information from you on exactly what you're
planning to do would help to determine an upper limit on how many
users you can handle.

At the moment the database dump is 4.1 meg.

I suspect the end result will be less than 10 meg including the user's
information.

Is there other size information you need?

Bob




----- Original Message -----
From: "Richard Huxton" <dev@archonet.com>
To: "Bob Pawley" <rjpawley@shaw.ca>
Cc: "PostgreSQL" <pgsql-general@postgresql.org>
Sent: Monday, December 03, 2007 8:18 AM
Subject: Re: [GENERAL] PostgreSQL on the internet


> Bob Pawley wrote:
>> Hi
>>
>> I am kicking around the idea of using PostgreSQL as a web based
>> service. Access to the site will be through a separate
>> application/interface.
>
> Why web-based if you're installing an application to the user's PC.
>
>> Can someone tell me what criteria I need to look at in order to
>> determine how many clients can be using the website, each with their
>> own database, at one time??
>
> How big is each database, and what will the users be doing with them?
>
> --
>   Richard Huxton
>   Archonet Ltd
>
> ---------------------------(end of broadcast)---------------------------
> TIP 5: don't forget to increase your free space map settings

Basically, the database will be used to build up an engineering document
called a P&ID which traditionally  comes in the form of a drawing. From the
database I'll create a drwawing which the user can, if he wants, convert
into a DXF file for use in AutoCad or Bentley drawing systems.

The database will also be used to transfer information to other engineering
databases yet to be completed.

Bob



----- Original Message -----
From: "Scott Marlowe" <scott.marlowe@gmail.com>
To: "Bob Pawley" <rjpawley@shaw.ca>
Cc: "PostgreSQL" <pgsql-general@postgresql.org>
Sent: Monday, December 03, 2007 8:35 AM
Subject: Re: [GENERAL] PostgreSQL on the internet


> On Dec 3, 2007 9:33 AM, Bob Pawley <rjpawley@shaw.ca> wrote:
>>
>> Hi
>>
>> I am kicking around the idea of using PostgreSQL as a web based service.
>> Access to the site will be through a separate application/interface.
>>
>> The user's interface will install the database on entry to the website.
>> When
>> the user exits the site, the database will be dumped to the user's
>> computer
>> and eliminated from the website. It seems to me that it is possible to
>> make
>> this dump and restore invisible, or mostly invisible,  to the user.
>
> You mean, I suppose, that you'll create a db on your server for the
> user, and load schema / data into that?  Then dump it out to the user
> when they're ready to go, and drop the db on your end?
>
> Seems pretty easily doable to me.
>
>> Can someone tell me what criteria I need to look at in order to determine
>> how many clients can be using the website, each with their own database,
>> at
>> one time??
>
> How much memory your db server has, how big the db will be, what kind
> of load it will have, how the db is tuned, etc...  I'd try it out
> after building a simple test case db and see how the system behaves
> with say 1, 2, 4, 10, 20 etc users.  Get a feel for it.
>
> I think a bit more information from you on exactly what you're
> planning to do would help to determine an upper limit on how many
> users you can handle.
>
> ---------------------------(end of broadcast)---------------------------
> TIP 4: Have you searched our list archives?
>
>               http://archives.postgresql.org/

Bob Pawley wrote:
> At the moment the database dump is 4.1 meg.
>
> I suspect the end result will be less than 10 meg including the user's
> information.
>
> Is there other size information you need?

Well, you'll want estimates of:
1. Total number of users (assuming you don't drop the database on the
server-side).
2. Total number of concurrent users
3. Their activity patterns

At a wild guess, your limiting factor will be one of:
1. User upload speed (they might be on a slow ADSL/wifi link)
2. Database creation

I'd be tempted to have the local app send a checksum to the server and
see if it needs to upload the DB at all.

--
   Richard Huxton
   Archonet Ltd