Oracle - Why should I use packages instead of standalone procedures or functions

Question

I searched google but did not find any satisfying answer as to why I should use packages.

I know that a package is a bundle of procedures, functions and different variables. As I understand it sort of corresponds to object in OOP. But of course there's nothing like instantiating different instances of a package so that each instance would have different property values and behave differently.

Then what is the advantage of using packages when I can just create a standalone procedure and call it independently?

Answer 1

Packages provide the following advantages:

1. Cohesion: all the procedures and functions relating to a specfic sub-system are in one program unit. This is just good design practice but it's also easier to manage, e.g. in source control.
2. Constants, sub-types and other useful things: there's more to PL/SQL than stored procedures. Anything we can define in a package spec can be shared with other programs, for instance user-defined exceptions.
3. Overloading: the ability to define a procedure or function with the same name but different signatures.
4. Security: defining private procedures in the package body which can only be used by the package because they aren't exposed in the specification.
5. Sharing common code: another benefit of private procedures.
6. We only need to grant EXECUTE on a package rather than on several procedures.

Answer 2

As described in Oracle docs, packages are good because of:

• modularity
• easier application design
• information hiding
• added functionality
• better performance

Details on each reason are explained in docs.