Re: Thick vs thin client - 11g R2

Sandy,

As you described, there are two issues:
1. connectivity to database using Oracle thin JDBC client.
2. characted set convertion making some characters a "garbage" or upside-down 
"?".

For Java application connectivity I definetly would suggest using JDBC thin 
driver. Why application doesn't start with thin driver? - there are few 
possibilities:
1. can not find driver's JAR files. Please verify if you have following files 
on 
your system:
ojdbc5.jar or ojdbc6.jar . Depending what Java version is running (1.5 or 1.6), 
you would need to use one or another.
2. application should specify classpath variable to those files - e.g
java -classpath $ORACLE_HOME/jdbc/lib/ojdbc5.jar MyApplication.class
Application server should have a configuration field where to specify classpath 
or specificaly define libraries for JDBC connection (defining connection pools 
or data sources).
3. Application should be connecting using connection string similar to:
jdbc:oracle:thin:@myhost:1521:sid

Note that Thin driver connectivity is very much different from sqlplus 
connection - don't even bother testing connection with SQLPlus or configuring 
tnsnames.ora if your application will be using thin driver anyways. 


Now about character set conversions: my understanding is that Java is using 
UCS-2 (2 byte unicode character encoding). It can have all variaty of 
characters. What character set your database support? - in what character set 
it 
was created? Let's assume it is created with WE8ISO8859P1 character set - it 
does not support Euro symbol or some French character. If somebody in your 
application enters French text, Oracle does it best to convert to matching 
characters (well, sometimes it doesn't comes as "best"). Some character might 
be 
converted to a question mark or upside-down "?".

Migrating database to a different character set is not an easy task - but that 
might apear the only way to support application that dials not only with ASCII 
characters - please take a look at Oracle documentation on this - 
http://download.oracle.com/docs/cd/B19306_01/server.102/b14225/ch11charsetmig.htm


Regards
Mike Navickas
Oracle&DB2 DBA





 
From:oracle-l-bounce@xxxxxxxxxxxxx [mailto:oracle-l-bounce@xxxxxxxxxxxxx] On 
Behalf Of Sandra Becker
>Sent: Thursday, September 23, 2010 12:25 PM
>To: oracle-l
>Subject: Thick vs thin client - 11g R2
> 
>Oracle - 10.2.0.4
>OS - SUSE10
>Platform - IBM zSeries mainframe
> 
>The decision was made recently to install the 11g R2 client on our application 
>servers.  I installed it, set up the tnsnames and tested connections to all 
>databases using SQL*Plus.  No problems at any step.  
>
> 
>Problems arose when they couldn't start the application using the thick 
>client, 
>only the thin client.  Due to the way our application was written, the thin 
>client allows non-printable characters into the tables that the application 
>cannot then pull back out.  They chose to ignore my advice that they 
>thoroughly 
>test and verify what was being affected.  Customers are complaining about 
>"corrupted" data.  The word I get is "we don't have time to fix the app, fix 
>oracle."  
>
> 
>Many people at the company are under the impression that 11g R2 client is 
>strictly a thin client.  Is that true?  How do you determine that?
>
>-- 
>Sandy
>Transzap, Inc.
>
>
>
>-- 
>Sandy
>Transzap, Inc.
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