Database Migration Is The Transportation Of Data From...

INTRODUCTION Database migration is the transportation of data from existing database to new database. With the advancement in technologies, upgrade in database data migration has become frequent and change in legal regularity is also a reason. To cope with better performance of the application and better outcome to the organization it is critical to achieve the migration in time, budget and allocated resources. Johny Morris, in [1] related data migration as â€Å"the selection, preparation, extraction, transformation, and permanent movement of appropriate data that is of the right quality to the right place at the right time and the decommissioning of legacy data stores.† Migrating data from source to destination is not just copy pasting the†¦show more content†¦The best practice for data migration is to use a tool or process that involves iterative approach and the answer is ETL, which is used during migration to extract data from legacy system then transform the data in required format and finally load in the target database. Some literatures verify the saying that ETL is more preferred tool for data migration. 41% of projects use ETL, on the second spot of most popular techniques being hand coded solutions with 27% [5]ETL has consolidated tools support[6]. The success of ETL tools is also due to the fact that Business Intelligence and Data Warehousing makes use of this paradigm [7]. [8] Discussed a substantial escalation in data quality based on the observation of statistical analysis before and after using automated ETL. After successful migration, the main issue lies with the integrity of quality data at target database which is done by data validation testing. A few of the existing methodologies of data validation testing is discussed in brief here in which some follows manual approach and other uses automated approach with their limitations. Some ongoing methodologies include: 1. Lines of code This is the simplest process for validation data. It uses COUNT operator and counts number of lines in both legacy and target databases and then compares them. If the rows in both databases are equal then it is considered as successful migration.