Re: [Pypgsql-users] c-jdbc (or rather sqlrelay ?)

[Dick K. <D.J...@ch...>]

On Sat, 2003-07-26 at 00:51, Karsten Hilbert wrote:
 
Hi  Karsten

I understand that I am comparing apples and oranges. And I do not expect
that anything is done. However, I like the discussion, and possibly,
unexpectedly, an answer comes from someone on the list.

Maybe I should have made it clear why I posed this strange question. We
have developed a product which uses Postgresql as a database, Python,
wxPython and Pypgsql. This works OK, no problems whatsoever.

However, some larger companies want to use the application as well. One
company has some 15 locations where people are working. Off course this
can be supported with high bandwidth online connections, but these
connections are expensive, and unreliable. Therefor I have been looking
for a way to get rid of the direct online connection. So, what I want is
a local connection to the database, with asynchronous updates to
databases that are in the same 'logical' cluster of databases. c-jdbc
looks like the proper candidate for this action, however no luck because
we developed using Python.....

Gains from this setup would be:
- if the connection goes down, work can continue
- all databases are mirrors of each other, so if a server has a hardware
problem, by rerouting the trafic, work can continue
- performance of the local setups would be significantly better
- Predictability of the responsetime would be better
- lower bandwidth requirements, as the updates are asynchronously done

On the downside:
- Extra hardware (diskspace and servers) is required
- complexity of the updates to all databases
- a short delay (minutes) between updates to one database and updates to
the others

I have looked at SQLRelay, and it does address some, but not all the
requirements, because there is no mechanism to direct update queries
transparently to other machines. Off course I want to hide the
complexity of updating multiple databases from my application. It looks
as though it can be used with pyPgsql. Is that the case?

Thanks for anyone responding

Dick Kniep