what is subprogram in pl sql

Subprograms are procedures or sub-routines (also called modules) in Oracle. A subprogram, like a regular stored procedure, can be stored in the database or can be called from the database. It is a named collection of PL/SQL code that is part of a PL/SQL package. Subprograms are similar to procedures but are limited in scope and cannot make changes to Oracle Objects (except for cursors).we are providing best oracle training in coimbatore with new updated syllabus with 15 years experience facallty

Advantages of subprograms in pl/sql

For a better understanding of PL/SQL subprograms and how they are used, let’s first look at how and when to use them, and then dive into how they are implemented and how they are different from SQL procedures.

What is a PLSQL Subprogram

What are Subprograms?

Subprograms are PL/SQL procedures or sub-routines that have the same name as a SQL user-defined function and are executed within the PL/SQL engine (except for named PL/SQL cursors). They are available to user-defined packages and can be run with either the CALL or EXECUTE keyword.

Note:

You cannot change the visibility or security of a subprogram using the ALTER SESSION statement; you can only alter the visibility and security of PL/SQL variables and cursors.

How Subprograms Are Different From SQL Procedures

PL/SQL subprograms cannot be used for general purposes; they are available for use only by procedures in the database or by client programs. Subprograms cannot modify the environment (Oracle Objects) except for the SELECT statement. In contrast, user-defined functions can modify the environment and Oracle Objects such as cursors.

What Is the Purpose of Subprograms?

Subprograms are used to encapsulate and simplify repetitive operations. If you have a routine that only contains logic, and you repeat that routine many times, then encapsulating the routine using a subprogram is a simple way to make it reusable and maintainable. Subprograms allow the developer to separate database logic from application logic, thus allowing a developer to use one database, multiple applications.

The Benefits of Subprograms

Subprograms are useful for many reasons:

A procedure or subroutine is called from PL/SQL and can perform data access tasks, which in turn can reduce the number of round trips to the database. For example, in an application, if you want to access an Oracle Database from your application, you can simply add a procedure that can perform a SELECT operation on your database and return the results to your application. This can be done with or without cursors.

For example, in an application, if you want to access an Oracle Database from your application, you can simply add a procedure that can perform a SELECT operation on your database and return the results to your application. This can be done with or without cursors. Subprograms can be used to separate the business logic from the physical logic. For example, in an application, if you want to do some mathematical calculations, you can create a subprogram that can perform those calculations and can be called from your application. In contrast, you can’t call a SQL procedure that performs mathematical calculations in your application without calling it from a stored procedure.

For example, in an application, if you want to do some mathematical calculations, you can create a subprogram that can perform those calculations and can be called from your application. In contrast, you can’t call a SQL procedure that performs mathematical calculations in your application without calling it from a stored procedure. Subprograms are useful for reusing the logic. For example, if you want to return some values from a SQL procedure, you can create a subprogram that can be called from your SQL procedure and return some of the results to your procedure.

For example, if you want to return some values from a SQL procedure, you can create a subprogram that can be called from your SQL procedure and return some of the results to your procedure. Subprograms can be used to enhance performance. For example, you can create a SQL procedure that accesses a large table; when the table is small, the procedure is quick to run; when the table is large, the procedure may take longer to run. You can create a subprogram that can first call the SQL procedure and get the results from the table. The subprogram can then return only the required information to your application.

For example, you can create a SQL procedure that accesses a large table; when the table is small, the procedure is quick to run; when the table is large, the procedure may take longer to run. You can create a subprogram that can first call the SQL procedure and get the results from the table. The subprogram can then return only the required information to your application. Subprograms can be called from a PL/SQL procedure. In other words, you can’t use subprograms to call a PL/SQL function. Instead, you can only use subprograms to call a PL/SQL subroutine or a subprogram.

The 5 Disadvantages of Subprograms

Subprograms are great in the sense that they can be used to perform a similar task; however, they have some limitations:
You can’t execute a subprogram. Unlike a stored procedure, a subprogram cannot be executed. The only way to execute a subprogram is to call it from within another PL/SQL procedure, except for named PL/SQL cursors.
Unlike a stored procedure, a subprogram cannot be executed. The only way to execute a subprogram is to call it from within another PL/SQL procedure, except for named PL/SQL cursors. Subprograms cannot be used to return SQL result sets. SQL procedures are not allowed to return result sets; you can only return a few data types from a PL/SQL procedure. However, PL/SQL subprograms can return multiple data types from the database.
SQL procedures are not allowed to return result sets; you can only return a few data types from a PL/SQL procedure. However, PL/SQL subprograms can return multiple data types from the database. Subprograms can be costly. The Oracle server requires more processing for executing a subprogram. In contrast, a SQL procedure is light in terms of server overhead.
A Subprogram Needs to be Declared Before You Can Use It