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I need the differences bettwen a FUNCTION, PROCEDURE and PACKAGE in Oracle. Which one is better to use in most of the times ? Thank you.
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Functions return a value, procedures don't, otherwise they're identical. A Package is a container that may have many functions and procedures within it. It provides useful capabilities such as scoping, interface definition and modular development. It's generally advisable to put your procedures and functions into packages with well designed interfaces. Procedures can return values via OUT params.
Jan 05 '10 at 12:24 PM
HillbillyToad
True, but that's not quite the same as a function returning a value. Since functions guarantee a return value in a standard way, they can be part of an expression, whereas procedures can't. e.g. SELECT sqrt(x) + sqrt(y) FROM dual;
Jan 06 '10 at 06:26 AM
Andrew Mobbs
So other than the return values there is no difference in between Functions and Procedures. I mean in point of performance.
Jan 06 '10 at 06:52 AM
OracleApprender
There's no intrinsic difference in performance, a single call to a function is just as fast as a single call to a procedure. However because functions can be used in expressions, they can be used to write poorly performing queries. For example, a function can be put in a WHERE clause, which may cause it to be evaluated many times. That isn't a performance issue with the function, the problem is in how it is being used.
Jan 06 '10 at 08:00 AM
Andrew Mobbs
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Package: A Collection of related variables,cursor,procedure,and functions Package will support oops features like encaplution and data hiding and function overloading(8.0), to declare package in 2 steps 1.package specification 2.package body SubPrograms: A set of pl/sql statements is stored in database and used to perform a task; there are 2 types of subprograms 1.Procedures 2.Functions Procedure:A subprogram type perform a task and will not return value. and used to perform dml operations on database Function:A subprogram type perform a task and may or may not return value,but it will return only one value.
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