Package

From Oracle FAQ

A package is a collection of procedures and functions stored within the database.

A package usually has a specification and a body stored separately in the database. The specification is the interface to the application and declares types, variables, exceptions, cursors and subprograms. The body implements the specification.

When a procedure or function within the package is referenced, the whole package gets loaded into memory. So when you reference another procedure or function within the package, it is already in memory.

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Example

CREATE OR REPLACE PACKAGE my_pack AS
  FUNCTION calc(n1 NUMBER, n2 NUMBER) RETURN NUMBER;
END;
/

CREATE OR REPLACE PACKAGE BODY my_pack AS

  FUNCTION calc(n1 NUMBER, n2 NUMBER) RETURN NUMBER AS
  BEGIN
    RETURN n1 * n2;
  END;

END;
/

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