AIX 5.3
some DB2 8.2 and some DB2 9.5

I am sure these are naive questions, but I am on uncertain ground.

Each of our systems has had Java installed on it, version 1.4.2 I believe.
The DB2 install also puts a copy of Java somehwere in the DB2 directories, version 1.5 from DB2 9.5.

We have a present need/requirement to have Java 6 (1.6) installed to use with Tomcat.
Would we replace the "system" Java 1.4.2 with 1.6, or replace the Java 1.5 from the DB2 install?

At least part of the reason for asking is that I have seen web postings that there may be issues with DB2 and Java 1.6.

Does it make sense that we have two versions of Java on a system?
Is the one in the DB2 directory only used for DB2 and the other is not?
Should the symbolic links to Java for the instance owner be changed to use the "system" Java as opposed to the Java from the DB2 install?

You can have multiple versions of java installed. For DB2, the java path is referenced in the JDK_PATH of the dbm config (db2 get dbm cfg) and the config for the admin server (db2 get admin cfg) if you created the administrative server instance (which is optional). Just make sure these point to a compatible version of java for DB2 use, and then use the other java for Tomcat.

However, it is usually not a good to idea to have an app or web server on the same server as DB2 because DB2 wants only real memory (not that fake virtual stuff) and DB2 needs to know how much real memory it has available for use.

Thank you.