SQL

SQL is Structured Query Language, which is a computer language for storing, manipulating and retrieving data stored in a relational database.

SQL is the standard language for Relational Database System. All the Relational Database Management Systems (RDMS) like MySQL, MS Access, Oracle, Sybase, Informix, Postgres and SQL Server use SQL as their standard database language.

Also, they are using different dialects, such as:

• MS SQL Server using T-SQL,
• Oracle using PL/SQL,
• MS Access version of SQL is called JET SQL (native format) etc.

SQL is widely popular because it offers the following advantages −

• Allows users to access data in the relational database management systems.
• Allows users to describe the data.
• Allows users to define the data in a database and manipulate that data.
• Allows to embed within other languages using SQL modules, libraries & pre-compilers.
• Allows users to create and drop databases and tables.
• Allows users to create view, stored procedure, functions in a database.
• Allows users to set permissions on tables, procedures and views.

SQL Process

When you are executing an SQL command for any RDBMS, the system determines the best way to carry out your request and SQL engine figures out how to interpret the task.

There are various components included in this process.

These components are:

• Query Dispatcher
• Optimization Engines
• Classic Query Engine
• SQL Query Engine, etc.

There are many popular RDBMS available to work with. This tutorial gives a brief overview of some of the most popular RDBMS’s. This would help you to compare their basic features.

MySQL

MySQL is an open source SQL database, which is developed by a Swedish company – MySQL AB. MySQL is pronounced as “my ess-que-ell,” in contrast with SQL, pronounced “sequel.”

MySQL is supporting many different platforms including Microsoft Windows, the major Linux distributions, UNIX, and Mac OS X.

MySQL has free and paid versions, depending on its usage (non-commercial/commercial) and features. MySQL comes with a very fast, multi-threaded, multi-user and robust SQL database server.

Features

• High Performance.
• High Availability.
• Scalability and Flexibility run anything.
• Robust Transactional Support.
• Web and Data Warehouse Strengths.
• Strong Data Protection.
• Comprehensive Application Development.
• Management Ease.
• Open Source Freedom and 24 x 7 Support.
• Lowest Total Cost of Ownership.

MS SQL Server

MS SQL Server is a Relational Database Management System developed by Microsoft Inc. Its primary query languages are:

• T-SQL
• ANSI SQL

Features

• High Performance
• High Availability
• Database mirroring
• Database snapshots
• CLR integration
• Service Broker
• DDL triggers
• Ranking functions
• Row version-based isolation levels
• XML integration
• TRY…CATCH
• Database Mail

ORACLE

It is a very large multi-user based database management system. Oracle is a relational database management system developed by ‘Oracle Corporation’.

Oracle works to efficiently manage its resources, a database of information among the multiple clients requesting and sending data in the network.

It is an excellent database server choice for client/server computing. Oracle supports all major operating systems for both clients and servers, including MSDOS, NetWare, UnixWare, OS/2 and most UNIX flavors.