We have a requirement to migrate an IMS database to Oracle. We would
like to write some in house tools for extracting IMS data and
transforming it to Oracle sqlldr format.

Is it an easy task?
What is the best way of achieving this?
Read IMS FDR files? or use some export utility for reading IMS
segments info ? Where can I get the format of these files?

Are there any third party tools available for this? How much it would
cost for a 10 gig databse?

Any help in this regard is appreciated.