Database maintenance and use

Databases hold data which are waiting to be read, updated or deleted. A database transaction is an operation that is carried out by a database management system. It has two primary uses – it helps in data recovery when there is a system failure and keeps the information in the database in tact when a failure or sudden termination of the system happens. It also isolates the database from applications accessing it so that wrong data may not be retrieved. A database transaction is also known as “all or nothing” in database parlance. It means a transaction has to totally finish before a change to the database occurs; if the transaction stops mid way for some reason, the database is in status quo. Most database systems are equipped with features to manipulate transactions within a database to maintain integrity of the data that has been recorded. Every transaction is made of one or more actions that read/ write into a database. The application using the system should check if the transaction that occurred is accurate and consistent before modifying the database.

With fast growing technology and new database models coming up every day, keeping a database updated becomes a challenge. Database migration involves upgrading to new systems. It refers to transferring and/ or rewriting data from an old to a new system. The database is transferred between computer systems and larger the database more complex this process becomes. Database migration involves multiple phases – right from designing, extracting, cleaning, loading and verifying.