Data Migration vs. Data conversion

Data Migration vs. Data conversion

When we need to enter data into oracle Apps, following are the few techniques:

• The Data can be entered using the application Screens (for small amount of data, like creating PO, entering sales orders using Oracle Apps screens).
• The data can be entered using Oracle’s Open System Interface (for regular operations e.g. for moving data from one module to another).
• The data can be stored in the database table directly (Not recommended by oracle and can be very risky, because on any event data is going to be stored in many tables and data should be validated before inserting into tables that may cause data integrity and inconsistency problem, sometimes it may corrupt the data completely.).
• Using third party tools like data loader (It is also can be used when data is relatively small (25-200 records) because it captures the keystrokes and works like manually entering the data into Oracle form but much faster as process is automated).

What is the need of Migration/Conversion?

Migration/Conversion are required when we are upgrading to one version to another (e.g. Oracle Apps 11.5.7 to Oracle 11.5.10) or moving data from some legacy system to Oracle Apps. There will be bulk  of data (sometimes millions or even more than that) that needs to be moved from one system to another  and  before moving the data it should be validated and only valid records should be entered into Oracle Apps.

If both the systems (Target and source) are not having same structure for data (Tables are not same/Table Structure is not same/The data is being stored in database is not same), it needs to be translated (e.g. upgrading from Oracle 11i to R12 where table structures are not same) then we say it as conversion (any kind of translation of data on Source data to make it suitable for Target system) otherwise migration.


What is Migration?


Migration of data means moving the data from one system to another using Interface Programs/APIs where both the systems have same structure of data.

Process of Migrating of data:
• Identify the data to be imported to new system (Business requirement).
• Extract the data into flat file/Staging table
• Load the data into Interface Table(using SQL* Loader/DB Link/Others) after validation(If loading the data using Interface)

What is Conversion?

Conversion of data means translating the data to suite target system (data should be formatted according to target system )  and then move the translated data using Interface Programs/APIs.
• Identify the data to be imported to new system (Business requirement).
• Extract into flat file/Staging table
• Translate/Convert/Format the data
• Load the data into Interface Table(using SQL* Loader/DB Link/Others) after validation(If loading the data using Interface) and then launch standard Interface concurrent program to load the data to Oracle Apps Base Tables
• If using API, fetch the data, validate it and then call API to import the data


How conversion/Migration and interface differ?


There are good numbers of parameter on which they can be categorized. Take few of them:
• Conversions/Migration are a one time event
• interfaces are ongoing
Occurrence in the project timeline
• conversions/Migration executed before production
• interfaces executed during production
Manner of execution
• Conversions/Migration are batch
• Interfaces may be batch or real time
• Conversion/Migration does have very complex, it’s totally depends upon the data mapping activity.
• Coordinating with other systems make interfaces more complex
• Maintenance of interface is bit cost intensive task.