how to find long running / active transaction.
I mean which is not commited yet ? ( unix)
TIA.

First find the application id (db2 list applications show detail). Then do a snapshot of the application. It will show you the current status and the number of SQL statements.

There is a freeware online monitor that will do the job nicely once you have the snapshot switches set on for the dbm configuration. The link for this program has been posted several times in this forum and you should be able to find it with a search, or you can try the Useful Stuff thread to see if you can find it.