Do we have to regenerate datamart datasources after upgrade manually

hello gurus!

recently we have upgraded our systems from BIW 3.0B TO BI 7.0.

the question which ponders me is

" DO WE NEED TO REGENERATE ALL THE DATA MART DATA SOURCES MANUALLY AFTER UPGRADE"????.

if its not required to manually regenerate then how does the system take care of it after upgrade.

Suggestions on this will be highly appreciated.

regards

Sairam