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Re: Updates via ODBC commands

From: Shachar Shemesh <psql(at)shemesh(dot)biz>
To: Ludek Finstrle <luf(at)pzkagis(dot)cz>
Cc: Postgresql ODBC list <pgsql-odbc(at)postgresql(dot)org>
Subject: Re: Updates via ODBC commands
Date: 2006-01-14 10:33:40
Message-ID: 43C8D384.1080903@shemesh.biz (view raw or flat)
Thread:
Lists: pgsql-odbc
Ludek Finstrle wrote:

>Yes. There is well known issue with dropping updateable cursor support.
>I'm sorry if you need updateable cursor you have to stay in using 07.03
>version (or maybe 08.00 - I don't know it exactly). I'm sure that there
>is no updateable cursor support in 08.01 version.
>  
>
Let me give you a short rundown of the customer. We started a project of
migrating one of their programs to Postgresql. Things were already
working when we hit a snag - performance for retreving large tables was
not acceptable. I managed to narrow it down to a problem in the ODBC
driver (7.4), where the lines are retreived one at a time, probably due
to the need to emulate updateable cursors.

The client decided to invest money in getting the problem solved. This
was about the time that Hiroshi quit the project. After some
consideration, they decided to freeze work on the particular product
they were working on, and work on another one of their projects, which
uses OLE DB. They sponsored the lion's share of the development of
PgOleDb to date (with my company, Lingnu, doing the actual work plus
putting a little pro bono work as well).

They now got back to their original product, and were suprised to find
out that what used to work no longer does. I described the work done on
the ODBC driver as a "rewrite". Assuming they decide to move forward
with the support, there are three possible avenues for continuing:
1. Fix the performance problem with 7.4
2. Add updateable cursors to 8.01
3. Switch the product to use OLE DB and add updateable rowsets there
(PgOleDb does not currently support updates either).

I'm currently assuming that any of the above would have to actually be
done by Lingnu with their sponsorship, but feel free to pleasently
surprise me. I'm fairly sure that I'll manage to convince them that 1 is
not a good idea (unless someone here thinks that the new version
under-performs in relation to the direct socket version). I believe they
will go with 2, in which case we'll obviously release any work we do.

>Regards,
>
>Luf
>  
>
       Shachar

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Next:From: Ludek FinstrleDate: 2006-01-14 13:53:23
Subject: Re: Updates via ODBC commands
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Subject: Re: call for creating test suite

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