Perl DBI (DataBase Interface) is the most common database interface for the Perl programming language. DBI was specified by Tim Bunce, in collaboration with others, starting in 1994, and is currently maintained across the Internet as a CPAN module in accordance with the Open Source model. DBD (DataBase Driver) serves as an abstraction layer which allows programmers to use nearly platform-independent SQL code in their applications.
The DBI and DBD Perl packages allow Perl programmers to view many database environments that are on the market in a uniform way. Each supported database environment is implemented as a DBD driver, in much the same way that hardware devices from multiple vendors can be used across CPU platforms. DBD implementations can be obtained by download from the Internet. DBD implementations exist for proprietary products such as Oracle, Microsoft SQL Server, IBM DB2, etc. and for free software databases such as PostgreSQL and MySQL.
The latest DBI module for Perl from CPAN is available for a range of operating systems.