Welcome to the world of Stored Procedures- Oracle, MS SQL,MySQL

Welcome to Stored Procedures

A stored procedure is a precompiled group of Transact-SQL statements, and is saved to the database .Programmers and administrators can execute stored procedures either from the SQL Server Management Studio or from within an application as required.
Once the stored procedure has been "stored", client applications can execute the stored procedure over and over again without sending it to the database server again and without compiling it again.
Stored procedures improve performance by reducing network traffic and CPU load.

Benefit	Explanation of benefit
Modular programming	You can write a stored procedure once, then call it from multiple places in your application.
Performance	Stored procedures provide faster code execution and reduce network traffic. Faster execution: Stored procedures are parsed and optimized as soon as they are created and the stored procedure is stored in memory. This means that it will execute a lot faster than sending many lines of SQL code from your application to the SQL Server. Doing that requires SQL Server to compile and optimze your SQL code every time it runs. Reduced network traffic: If you send many lines of SQL code over the network to your SQL Server, this will impact on network performance. This is especially true if you have hundreds of lines of SQL code and/or you have lots of activity on your application. Running the code on the SQL Server (as a stored procedure) eliminates the need to send this code over the network. The only network traffic will be the parameters supplied and the results of any query.
Security	Users can execute a stored procedure without needing to execute any of the statements directly. Therefore, a stored procedure can provide advanced database functionality for users who wouldn't normally have access to these tasks, but this functionality is made available in a tightly controlled way.

 You can find detailed stored procedures of popular database systems here:
a. Oracle  : http://codingbasics.blogspot.com/2011/07/stored-procedures-in-ms-sql.html
b. MSSQL : http://codingbasics.blogspot.com/2011/07/stored-procedures-in-oracle.html
c. MySQL : http://codingbasics.blogspot.com/2011/07/stored-procedures-in-mysql.html