Oracle: Does a 10g oracle client work with an 11g server?

Question

This is the reciprocal to this question. Currently, I am trying to use the instant client for Mac, version 10.2. There\'s no 11g version for Mac, as of now, based on this page(y

Answer 1

I would certainly say it should. The SQL*Net protocol it uses is essentially unchanged. Here's an example of me connecting an Oracle 9 to an Oracle 10 server.

oracle@cammi:~$ sqlplus "urs/urs@THANOS_URS"

SQL*Plus: Release 9.2.0.8.0 - Production on Thu Jun 25 05:55:57 2009

Copyright (c) 1982, 2002, Oracle Corporation. All rights reserved.

Connected to: Oracle Database 10g Enterprise Edition Release 10.2.0.4.0 - 64bit Production With the Partitioning, Data Mining and Real Application Testing options

According to the guys at "http://www.experts-exchange.com/"...

11 can talk to 11,10,9
10 can talk to 11,10,9,8
9 can talk to 11,10,9,8,7
8 can talk to 10,9,8,7
7 can talk to 9,8,7

According to Oracle forums, this is defined in Metalink DocID 207303.1, which provides a comprehensive client/ server compatibility matrix. I don't have Metalink access sadly, so I can't confirm this.

If you are having connection troubles, I suggest you start with the Oracle alert log on your server machine. To find the location of your oracle alert log:

SQL> select value from v$parameter where name = 'background_dump_dest';

Also, you'll probably get something useful out of enabling listener tracing:

$ lsnrctl
LSNRCTL> set trc_level ADMIN

The trace file on my Solaris Oracle 10 install is found in:

$ORACLE_HOME/network/trace/listener.trc

You can view it directly or use the trcasst program to "format" it. Note that ALL of this is on the server, not your client side.

Hope this helps.