Can we change schema ownership ?
I mean,if set of objects owned by 'db1schema' can we change it to 'db2newuser' schema ?
if so how ?
Please help.
thanks in advance.

Not aware of any such command which can do this but you can use db2move utility to extract data and table structure and then change one of the log file generated by utility. Do find/replace and specify new user so when you do import tables are created for that user and data loaded.

There are other ways to do the same, db2move is only one such.

dollar

OK.then can any user inpersonate other user so they don't need to make like :
select db2usr1schema.table1 ( db2user2 makes this query) instead they can just impersoname 'db2usr1schema' owner and make simple by:
select table1 , as if it were created by him ?

Yes, look as SET CURRENT SCHEMA SQL Command (in SQL Reference manual).

Andy