Database

Database is a file used to store records of information, with each record containing multiple data fields.

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What is a Database?

A file used to store records of information, with each record containing multiple data fields. The most popular type of database is the relational database, in which the records are stored in tables that are related to each other using primary and foreign keys.

A primary key is the field in each record that uniquely defines the record. (For example, a part number might be used as the primary key in a table that holds the price of each item a company sells.)

A foreign key is a field in another table that matches the first table’s primary key, creating a relationship between the two. An application for creating and managing relational databases is called a relational database management system (RDBMS).

How Databases work

Records are like the rows of a table. Each record is a collection of information about some physical system or logical object. Field names are like the column names of a table. Each field name represents a property or attribute of the system or object. Databases are widely used by businesses for storing information about inventory, orders, shipping, accounting, and so forth.

Microsoft SQL Server is Microsoft's enterprise-level RDBMS. SQL Server databases are stored on devices. Each computer running SQL Server has four system databases plus one or more user databases installed on it. The system databases are as follows:

  • The master database, which is used for tracking system-wide information.
  • The tempdb database, which is used for temporary working storage and sort operations.
  • The model database, which is a template for creating new databases.
  • The msdb database, which is used to store system data and transaction logs and to support the SQL Server Agent service and its scheduling information. The msdb database is stored on two devices, the Msdbdata system device and the Msdblog system device.
NOTE

The term «database» can have different meanings for different vendors. In Oracle products, for example, «database» refers to the entire Oracle DBMS environment. In SQL Server, databases provide a logical separation of data, applications, and security mechanisms, while in Oracle this separation is achieved using «tablespaces».

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