SQL Server applications begin with databases. As a fundamental component in your data-dependent applications, understanding how information is stored in SQL Server and the most efficient layout for your database is critical to its performance. SQL Server 2000 has two types of databases: system and user. System databases contain the configuration information for your server, your databases, and features such as SQL Server Agent and replication. Every installation of SQL Server includes the Master, msdb, Model, and TempDB system databases. User databases are the databases that are created for your applications to store and manage data.

Databases in SQL Server are made up of data and log files, which are responsible for storing the data and transaction logs for your database. Transaction logs are records of changes to the data in your database. Transaction logs are useful for recovery because they record each change to the data. Data files are used to store the actual data contents of your database. Data files are physically made up of 8K pages. With the exception of text and image data, the 8K-page size represents the maximum single record size. Pages of data file space are allocated to tables and indexes in groups of eight, which is called an extent. In case a table or index does not require 64K (8 x 8K) of storage, SQL Server supports mixed extents, which allow for a single extent to be allocated to a maximum of eight different tables or indexes for more efficient use...