Interview Questions

The enter and PF keys transmit data from the screen; the PA keys tell CICS that a terminal action took place, but data is not transmitted.

A collection just like an array is an ordered group of elements of the same type. Each elements position is determined by a unique subscript.

Index by tables:- They are similar to hash arrays that allows to search for subscript values using arbitrary numbers and strings.

They can be declared as:

TYPE type_name IS TABLE OF element_type [NOT NULL]

INDEX BY [BINARY_INTEGER | PLS_INTEGER | VARCHAR2(size_limit)];

INDEX BY key_type;

Example:

TYPE studenttyp IS TABLE OF emp%ROWTYPE

INDEX BY BINARY_INTEGER;

stud_tab studenttyp;

Nested tables:- they hold random number of elements and use sequential numbers as sub scripts.

They can be declared as:

TYPE type_name IS TABLE OF element_type [NOT NULL];

Example: TYPE employee_type IS TABLE OF NUMBER INDEX BY VARCHAR2(64);

Varrays: Holds a fixed number of elements which can be changed in run time. 

They can be declared as:

TYPE type_name IS {VARRAY | VARYING ARRAY} (size_limit) OF element_type [NOT NULL];

Example: TYPE Calendar IS VARRAY(366) OF DATE;

Node.js is a framework for web applications built on Google Chrome's JavaScript Engine(V8 Engine).

Node.js is comes with runtime environment on which a cript based on javascript can be interpreted and executed (It is analogus to JVM to JAVA byte code). This runtime environment allows to execute a JavaScript code on any machine outside a browser. Because of this runtime of Node.js, JavaScript is now can be executed on server also.

Node.js is provides a rich library of various javascript modules which eases the developement of web application using Node.js to greater extents.

The LOAD command retrieves an object program from disk and loads it into main storage - it's primarily used for a constant table that will be available system-wide.

- By using method overriding a sub class can change the definition of super class method.

- By using overriding a sub class can modify the functionality of the super class.

The LMHOSTS file is a static method of resolving NetBIOS names to IP addresses in the same way that the HOSTS file is a static method of resolving domain names into IP addresses. An LMHOSTS file is a text file that maps NetBIOS names to IP addresses; it must be manually configured and updated.

-  A stored procedure can accept parameters while a trigger cannot.
-  A trigger can’t return any value while stored procedures can.
-  A trigger is executed automatically on some event while a stored procedure needs to be explicitly called.
-  Triggers are used for insertions, update and deletions on tables while stored procedures are often using independently in the database.
-  A trigger cannot be written in a stored procedure. However, the reverse is not possible.