Backup and Recovery Best Practices › Microsoft SQL Server Database Basics

Microsoft SQL Server Database Basics

To achieve optimal results using Arcserve Backup to back up your Microsoft SQL Server databases, the following database fundamentals are provided.

A database is a collection of tables, which are comprised of rows or records. Each row is made up of columns that contain some sort of structured information about a record. Database data is stored across two operating system files -- data files and log files:

• Data Files--Contain user data and metadata.
  • Primary Data File--Contains information about the database itself including references to the other files comprising the database. In a simple database, user-defined data and objects can be stored in the Primary Data File, though Secondary Data Files should be used for such data. Each database has one primary data file (.mdf).
  • Secondary Data Files--Contain user-defined data and objects, for example, sales figures, employee information, or product details. Use secondary data files (.ndf) to store database information across multiple disks and to manage database growth.

  Data Files can include full-text search catalogs, which allow you to search on the full-text catalogs stored with a database. Though not actually data files, FILESTREAM data allows you to store unstructured data including video, photographs and other documents usually stored outside the database and are treated as files in the database.

• Log Files--Contain information at the transaction level required to restore your database to a specific point in time in the event of a disaster. There is at least one log file (.ldf) per database though you may add more as needed.

Though SQL Server supports single-disk systems, you should store your Data and Log Files on separate disks.