Database Administrators...
A database administrator is an individual responsible for maintaining the RDBMS system. The DBA has many different responsibilities, but the overall goal of the DBA is to keep the server up at all times and to provide users with access to the required information when they need it. The DBA makes sure that the database is protected and that any chance of data loss is minimized.
A DBA can be someone who has concentrated in the area of database design and administration, a programmer who took over the responsibility of maintaining a database during project development and enjoyed the job so much that he switched, or system administrator who was given the added responsibility of maintaining a Database. DBAs can even come from unrelated fields, such as accounting or the help desk, and switch to Information Systems to become DBAs.
- A good understanding of the operating system the database is on, such as Microsoft Windows NT
- Knowledge of Structured Query Language (SQL)
- Sound database design
- General understanding of network architectures (for example, Client/Server, Internet/Intranet, Enterprise)
- Knowledge about the database itself, such as Microsoft SQL Server, Oracle, DB2, MySQL, etc.
The following sections examine the responsibilities of the database administrator.
The DBA is responsible for installing the database software or upgrading an existing Database Server. The DBA is responsible for ensuring that if the upgrade is not successful, the Database Software can be rolled back to an earlier release until the upgrade issues can be resolved. The DBA is also responsible for applying necessary service packs. A service pack is not a true upgrade, but an installation of the current version of software with various bug fixes and patches that have been resolved since the product's release.
Monitoring the health of the database server means making sure that the following is done:
- The server is running with optimal performance.
- The error log or event log is monitored for database errors.
- Databases have routine maintenance performed on them, and the overall system has periodic maintenance
- performed by the system administrator.
- Using Storage Properly
Most databases allow you to automatically grow the size of your databases and transaction logs, or you can choose to select a fixed size for the database and transaction log. Either way, maintaining the proper use of storage means monitoring space requirements and adding new storage space (disk drives) when required.
Backup and recovery are the DBA's most critical tasks; they include the following aspects:
- Establishing standards and schedules for database backups
- Developing recovery procedures for each database
- Making sure that the backup schedules meet the recovery requirements
- Managing Database Users and Security
The DBA works tightly with server administrators to add user logins to the database. In non-NT domains, the DBA adds user logins. The DBA is also responsible for assigning users to databases and determining the proper security level for each user. Within each database, the DBA is responsible for assigning permissions to the various database objects such as tables, views, and stored procedures.
It is important for the DBA to work closely with development teams to assist in overall database design, such as creating normalized databases, helping developers tune queries, assigning proper indexes, and aiding developers in the creation of triggers and stored procedures. A good DBA will show the developers how to use and take advantage of database index tuning.