Technology Questions

It Return true if the argument is not a number.

CDATA - (Unparsed) Character Data

The term CDATA is used when you dont want some text data to be parsed by the XML parser.

A CDATA section starts with "<![CDATA[" and ends with "]]>": 

Even though both PL/SQL and Java (or) .NET can be used, PL/SQL stands above these two in terms of integration overhead. This is because Java is an open source proprietary and Data manipulation is slightly faster in PL/SQL than in Java. 

A throw is used to throw an exception manually, where as throws is used in the case of checked exceptions, to tell the compiler that we haven't  handled the exception, so that the exception will be handled by the calling function.

ClassName refName = new ClassName();

or

ClassName refName;

refName = new ClassName();

1)standered table

2)index table

3)hashed table

4)sorted table

Oracle NOT NULL is used on a column to ensure that the value for that column can never be NULL.
Example:
Below, the constraint is that the id should never be NULL. If it is, oracle throws an error.
create table employee ( id number NOT NULL, Name varchar(200) );

An abstract class can have instance methods that implement a default behavior. An Interface can only declare constants and instance methods, but cannot implement default behavior and all methods are implicitly abstract. An interface has all public members and no implementation. An abstract class is a class which may have the usual flavors of class members (private, protected, etc.), but has some abstract methods.