commit issue with import in db2

Hi

Please help me with this scenario:

Problem :
I have around 10 tables(having relationship with each other) and a data
asc file for each. i use import utility to load all the data one by one
for each table...these files are almost 1gb each. I need to commit data
only when all the 10 table imports are done as the data is relational
dependant , not after each table import is finished as the import
commits as it is done with the inserts/updates for one table...

The tables are in use by the users  so can drop relationships, Can i
use import in stored procedure.? or if these all imports can be clubbed
in a transaction. The data is either inserted or
updated(using  insert_update option of import)

please advice.