Data migration is the process of transferring data between storage types, formats, or computer systems. Data migration is usually performed programmatically to achieve an automated migration, freeing up human resources from tedious tasks. It is required when organizations or individuals change computer systems or upgrade to new systems. To achieve an effective data migration procedure, data on the old system is mapped to the new system providing a design for data extraction and data loading. The design relates old data formats to the new system's formats and requirements. Programmatic data migration may involve many phases but it minimally includes data extraction where data is read from the old system and data loading where data is written to the new system. After loading into the new system, results are subjected to data verification to determine that data was accurately translated, is complete, and supports processes in the new system. During verification, there may be a need for a parallel run of both systems to identify areas of disparity and forestall erroneous data loss. Automated and manual data cleansing is commonly performed in migration to improve data quality, eliminate redundant or obsolete information, and match the requirements of the new system. Data migration phases (design, extraction, cleansing, load, verification) for applications of moderate to high complexity are commonly repeated several times before the new system is activated.
See also
Tools
- Scriptella ETL: an open source ETL (Extract-Transform-Load) and script execution tool.
- ETL Integrator: JBI-enabled open source ETL (Extract-Transform-Load) tool, which can be used for data migration in Service Oriented Architecture (SOA) environments.
- Data Migration Toolkit (DMT): a GUI-based Java utility for migrating files and database data (free of charge and demonstrating the data migration process practically).
- Talend: an open source ETL (Extract-Transform-Load) and script execution tool.
- DBMSMigrator: Legacy Data and Database Migration for Migrating IMS, IDMS, ADABAS, VSAM, Datacom, etc.
