Re: MS Oracle Data Provider BUG: Data corrupt after 16 rows with O

From: philipp (philipp_at_discussions.microsoft.com)
Date: 07/20/04 

Date: Tue, 20 Jul 2004 06:30:05 -0700

Hello Frans , hello Angel,

thank you for all your replies. It may help you to know how the data got into the database. I tried several ways to fill in the data into the table:

1. Initial data were a dump from a former 8i UTF8 database. They were imported into the 9i database without any errors (i tried 8i Client as well as 9i client).

2. Second way i tried is the following: I made TOAD to generate an sql script from the data with a lot of insert statements. Via TOAD (8i Client as well as 9i Client, tried both on different machines) i loaded the data into the table by the sql script. Before, I tried truncating the table as well as dropping and recreating the table.

To me, it still seems to be an ODP / MSDPO issue OR an Oracle Client (9.2.0.1.) issue. I cannot imagine how simple ascii-sql-scripts could lead to corrupt data encodings or whatsoever. Also I cannot imagine that the database itself (9.2.0.4 on W2003Server) makes such simple errors in the Online-Converting. Although, this may be a hint, the problem disappears when I tell the client (via registry) to use WE8MSWIN1252 instead of UTF8.

Another hint may be the following: We had exactly the same problem 1,5 years ago when we were using ODP and 8i Client / 8i Database. The second prefetch of rows lost one or some bytes and data were corrupt. A former team member informed me that the problem disappeared when they switched from ODP (at that time) to MS Data Provider.

Any other ideas ?

Angel, you had a similar thread in another group 0,5 years ago with a developer from poland. Could you help him at that time? How?

Thanks a lot in advance,

Philipp.

"Angel Saenz-Badillos[MS]" wrote:

> I was thinking more along the lines of invalid UTF 8 data having been
> inserted into the Oracle database. This is surprisingly easy to do and hard
> to catch. By default some providers and sqlplus are not safe to use with
> Unicode into a UTF8 database, when you insert Unicode data it inserts
> "garbage". This is hard to catch because reading back the "garbage" data
> with the same provider that you used to insert it will return the data you
> where expecting. True Unicode providers like odp.net and the oracle managed
> provider will instead return the "garbage". The best way to verify this is
> to do a "select dump(<row>, 1016) from <yourtable>" and use a utf8
> converter to verify that the data in the database is correct.
>
> --
> Angel Saenz-Badillos [MS] Managed Providers
> This posting is provided "AS IS", with no warranties, and confers no
> rights.Please do not send email directly to this alias.
> This alias is for newsgroup purposes only.
> I am now blogging about ADO.NET: http://weblogs.asp.net/angelsb/
>
>
>
>
> "Frans Bouma [C# MVP]" <perseus.usenetNOSPAM@xs4all.nl> wrote in message
> news:xn0dkyszusv731000@msnews.microsoft.com...
> > Angel Saenz-Badillos[MS] wrote:
> >
> > > It is really strange that both ODP.NET and the Oracle Client managed
> > > provider are running into this question, especially since your database
> is
> > > using UTF8. How did you insert the data? Can you do a select dump to get
> the
> > > actual value inserted in the database and verify that the data was
> inserted
> > > correctly?
> >
> > ... perhaps it's something with the oracle client (thus not the provider,
> > but the actual client software the provider talks to) settings.
> >
> > FB
>
>
>

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