Loading Bulk Data


For Production migration , we need to select around 50-30 thousand rows from one table … and update them in another table.
Just want to know will loading such large amount of data at one go will cause any problem ?
(This will be done using two adapter service , select and update)

As i was just trying to load about 7-8 thousand rows in test env the service hung up.

Can anyone suggest me a better and faster method.