Database Upgrade to Oracle 11g

Discussion of open issues, suggestions and bugs regarding usage of dbExpress drivers for Oracle in Delphi and C++Builder
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Database Upgrade to Oracle 11g

Post by mmalinow » Fri 12 Sep 2014 16:46


We are upgrading the Oracle database that our Delphi applications connect to through dbExpress for Oracle. WE are going from 7.3.4 to 11g (NLS_CHARACTERSET = UTF8). We are presently using version of dbexpoda40.dll and the driver parameter we have been using for ServerCharSet=WE8ISO8859P1.

1. Do you advise updating our dbexpoda40.dll to the latest version for the upgrade to 11g? Any performance issues if we don't?

2. What ServerCharSet parameter do you advise using for the 11g - UTF8 database? We have been using WE8ISO8859P1 for 7.3.4.

Can you recommend any knowledge base documentation regarding this ServerCharSet setting and specifically it's effect on using our application with other regional settings such as Japanese? Does this setting have to correspond to the server character set or to the Windows client code page? Additionally there are settings for "unicodeenvironment" and "useunicode" We are actually unsure on all of these.

Thank you very much for your assistance,
Michael Malinowski
Production Resource Group

Devart Team
Posts: 5530
Joined: Tue 10 Aug 2010 11:35

Re: Database Upgrade to Oracle 11g

Post by AlexP » Thu 16 Oct 2014 08:34

1) We are always working on performance improvement, so the performance in the new version is higher than in the previous one.
2) If you use a UTF8 database, you should specify the ServerCharSet that is specified in the parameter NLS_CHARACTERSET (SELECT * FROM V$NLS_PARAMETERS)
3) You should change the driver charset depending on the server charset. These parameters are described in the documentation (Readme.html )

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