Different types of Structured Query Language (SQL) software have developed for various reasons. SQL is open source software, meaning its development and usage are controlled by a global, often volunteer, group of developers. Other groups can modify the software to better perform tasks or perform actions specific to their needs. SQL is a non-procedural language, meaning the user specifies the desired result, and the software handles the procedures required to deliver the information. The user benefits from the ease of use; however, results can vary slightly between implementations.
Standard SQL is defined by the American National Standards Institute (ANSI). The mission of ANSI is to enhance United States productivity and competitiveness. It tries to provide a common reference for SQL software. ANSI periodically reviews and publishes accepted upgrades to the language.
Due to the many versions of SQL software, some industrial experts believe there is no standard. Programmers often have to refer to tables of variations when writing software that will be used on multiple platforms. A listing of the common implementations of SQL software follows.
Postgre SQL, also referred to as Postgres, was written to support its authors’ database software, called Ingres. This version strives to be compliant with the standard SQL software. It is compatible with virtually all major business-level operating systems. Many features are implemented to enhance its support of very large enterprises.
DB2 is the IBM offering of SQL. It is geared for mixed workloads on distributed systems, allowing multiple users on various hardware platforms to work together. It supports Linux, Unix, and Windows and has added support for z/OS. Informix is the IBM solution for online transactional processing. Microsoft uses a propriety version called Transact-SQL as the primary query language for its relational database management system (RDBMS).
MySQL is an open source implementation of SQL software designed for multi-user access to a number of databases. It is often bundled with other free software or servers that host smaller enterprises’ and individuals’ Web sites. These servers often employ the coordinated system of the Linux operating system, Apache server, MySQL database, and PHP scripting language (LAMP).
Oracle is the general term for the Oracle Company’s RDBMS. It was the first commercial implementation of the SQL software and has remained very popular. The software is generally compliant with standard SQL. Oracle supports a number of platforms, including Windows, Linux, Mac OS X, and Sun Solaris.