PL/SQL

In this post we will learn about PLSQL language, What is PL/SQL, and Why Use PLSQL

What is PL/SQL

• PL/SQL is Oracle’s proprietary extension to SQL that allows for procedural language capabilities
• It gives all the features of modern software engineering such as data encapsulation, exception handling, information hiding and object orientation
• It is also available in IBMDB2 and Times ten-in memory databases
• PL/SQL stands for “Procedural Language extensions to the Structured Query Language”

Why Use PLSQL

• Integration with development tools like Oracle forms, Reports
• Multiple statements can be grouped into a single plsql block   and sent to the oracle server which results in less network traffic
• Modularized program development: Breakdown the complex logic/problem into a set of manageable, well-defined, logical modules and implement them using blocks
• Portability: Since it is native to the Oracle server, it can be moved easily
• It provides procedural language control structures like if condition, looping
• It has the capability to handle errors and raise an exception based on it

How PLSQL Works

• PLSQL engine is the technology which works on the PLSQL Blocks. PLSQL engine reads the block and converts it into machine code.
• PLSQL engine is present in Oracle Database and Oracle Tools Like Oracle forms
• The engine is invoked based on where you are executing the code. If it is through SQLPLUS in Oracle, then the PLSQL engine in the Oracle Database works on it
• When you submit the PLSQL code to the Oracle server. PLSQL engine in the Oracle Server read the code, compiles it and then separately the SQL statement and sends it to the SQL engine processor. The Procedural part is handled by the PLSQL engine only
• This is illustrated below using the simple diagram

Summary

• PLSQL is an extension to SQL
• PLSQL engine process the PLSQL Block
• Integration, Portability, error handling and Improved performance are some of the benefits of it

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Oracle PLSQL documentation
Oracle PlSQL interview question