PUNE, INDIA: OBVIOUS but still challenging is the data bite that comes along when one chews in a legacy switch-over morsel.

Data held in legacy systems is no doubt an important business resource. 

Yogesh Agarwal, CP, Command Central product group, Symantec agrees that this component is a major area of attention when one is migrating to a new set-up.

And why not, because typically a legacy system comprises mission-critical business knowledge which cannot be fiddled with.

Pushing the ‘migrate’ button without being sure about the data part can easily land a CIO in a Catch 22 setting.

There’s a lot that can go helter-skelter.

You can be in the middle of a series of migrations and pop comes a torrent of unforeseen data glitches.

Or while you think you have successfully migrated a big block of data, and then someone wakes up and smells that customer has 'forgotten' to mention a mandatory field due to which subsequent transaction-no-honor situations would come up.

There could be a zillion errors that might go live along with the new system if data migration is treated with inadvertence. 

Issues can range from data transformation complexity, migrating live data without downtime, taking care of duplicate data, physical access to data bases D/b heterogeneity, obsolescence and consequent non-sync situations with new-generation D/b or simply a GIGO (Garbage in Garbage Out) situation.

Many techniques have evolved over a period of time, experiences and genres to tackle the data component. These range from Database First (Forward Migration) method, incremental migration, the Database Last (Reverse Migration) Method, etc.

Choose whatever, but choose smart.

Addressing data issues well during migration could make all the difference between information and Junk.