Often you came across the term Data Migration, specially is its about web world and Internet. The process of Data transferring data between computer systems, or any other storage types is called Data Migration. To decrease human work data migration is often performed programmatically known as automated migration. Data migration is important specially when organizations or individuals upgrade or change to new systems. In order to execute an effective, data on the old computer is mapped to the new system to provide a design for data loading and data extraction. The given design will relate old data formats to the new system’s requirements and formats. There are many steps in programmatic data migration, but two of the main steps are data extraction in which data is read from the old system and second is data loading where data is loaded on the new system. Next step is data verification where it is confirmed whether data is accurately transferred or not. Automated data cleaning is preferred in order to reduce redundant information and to improve data quality. All the data migration phases are repeated again and again before the new systems is organized.

There are many kind of Data Migration available in the market. Data is stored on various kind of files and then generated with the help of software applications which finally supports business processes. According to these process data migration is divided in four categories as:

• Database Migration: Data can be transferred from one database dealer to another or may be the database software needs to be changed. upgradation of database software is not used usually but it happens in major upgrades. Data formats changes significantly so this process needs physical transformation. Modern applications needs checking before data migration, like change from DB2 to SQL Server or from Oracle to MySQL requires testing cycle. The testing cycle should confirm that both non-functional and functional performance is not affected badly.

• Storage Migration: To take advantage of more efficient storage technologies many business choose to reduce the physical media. In this type of migration physical blocks of data are moved from one tape to another mostly using virtualization techniques. Data format and content is not changed usually and all the process is done with minimal impact of the layers of data.

• Business Process Migration: Business process are executed in a combination of application systems and human actions. These actions are often coordinated by business management tools. When changes occurs in these actions they require the movement of data from one database to another to imitate the change to the information and organization about operations, customers, products. These kind of large data migration changes occurs when large acquisitions and mergers or business optimization response to the competitive world.

• Application Migration: this kind of migration means changing an application vendor, for example for example if you want to a new ERP platform you will have to change almost every application which suits its own precise data model. Commercial off the shell packages are generally configured in order to make the application to be sold to every kind of genre. To protect the integrity of the data APIs (Application Programming Interfaces are also supplied.