Oracle: Procedures, Functions & Packages

Procedures, Functions & Packages ;
27. What is a stored procedure ?
A stored procedure is a sequence of statements that perform specific function.
28. What is difference between a PROCEDURE & FUNCTION ?
A FUNCTION is alway returns a value using the return statement. A PROCEDURE may return one or more values through parameters or may not return at all.
29. What are advantages fo Stored Procedures /
Extensibility,Modularity, Reusability, Maintainability and one time compilation.
30. What are the modes of parameters that can be passed to a procedure ?
IN,OUT,IN-OUT parameters.
31. What are the two parts of a procedure ?
Procedure Specification and Procedure Body.
32. Give the structure of the procedure ?
PROCEDURE name (parameter list.....) is local variable declarations BEGIN Executable statements.
Exception. exception handlers end;
33. Give the structure of the function ?
FUNCTION name (argument list .....) Return datatype is local variable declarations Begin executable statements Exception execution handlers End;
34. Explain how procedures and functions are called in a PL/SQL block ?
Function is called as part of an expression. sal := calculate_sal ('a822'); procedure is called as a PL/SQL statement calculate_bonus ('A822');
35. What is Overloading of procedures ?
The Same procedure name is repeated with parameters of different datatypes and parameters in different positions, varying number of parameters is called overloading of procedures.
e.g. DBMS_OUTPUT put_line
36. What is a package ? What are the advantages of packages ?
Package is a database object that groups logically related procedures. The advantages of packages are Modularity, Easier Applicaton Design, Information. Hiding,. reusability and Better Performance.
37.What are two parts of package ?
The two parts of package are PACKAGE SPECIFICATION & PACKAGE BODY.
Package Specification contains declarations that are global to the packages and local to the schema. Package Body contains actual procedures and local declaration of the procedures and cursor declarations.
38. What is difference between a Cursor declared in a procedure and Cursor declared in a package specification ?
A cursor declared in a package specification is global and can be accessed by other procedures or procedures in a package. A cursor declared in a procedure is local to the procedure that can not be accessed by other procedures.
39. How packaged procedures and functions are called from the following?
a. Stored procedure or anonymous block b. an application program such a PRC *C, PRO* COBOL, c. SQL *PLUS
a. PACKAGE NAME.PROCEDURE NAME (parameters);
variable := PACKAGE NAME.FUNCTION NAME (arguments);
EXEC SQL EXECUTE
b. BEGIN
PACKAGE NAME.PROCEDURE NAME (parameters)
variable := PACKAGE NAME.FUNCTION NAME (arguments);
END;
END EXEC;
c. EXECUTE PACKAGE NAME.PROCEDURE if the procedures does not have any
out/in-out parameters. A function can not be called.

40. Name the tables where characteristics of Package, procedure and functions are stored ?
User_objects, User_Source and User_error.