Dear all,

I am running into a tricky situation where i need to migrate data from a legacy systems (15 yo) which uses Db2 (45 GBs) to a new DB2 system. However, the old database was designed really bad e.g. no primary or foreign keys at all. Most fields are VARCHAR so data in there needs cleansing too. People who designed the legacy DB have left with no document whatsoever for me.

We have a new design system using Db2 as DB with everything we know inside out, but i still need to migrate data from the old DB2. Today we do data mapping, but are still not sure that we covered the old program and its DB enough. To make it worst, we need to synchronize the two systems for a while before we can decide that we can decommission it.

At this stage i can only get my team to play with the old system and trace SQL, but it taking so long and i am not sure that my team have cover all conditions. So any comment, guideline or recommended tool will be greatly appreciated. If you have similar experience to share that will be great.

Thank you
Kai

Since you managed to provide absolutely no details about your systems, I can only suggest using some sort of an ETL tool, possibly coupled with replication.