Technology Questions

Primary key : a relational database constraint. Primary key consists of one or more columns that uniquely identify a row in the table. For a normalized relation, there is one designated primary key.

Unique index: a physical object that stores only unique values. There can be one or more unique indexes on a table.

Because SALARY is not declared to have NULLs and the employees for whom the salary is not known are also counted.

Multiple inheritance is a feature in C++ by which one class can be of different types. Say class teaching Assistant is inherited from two classes say teacher and Student.

Super global arrays are the built in arrays that can be used anywhere. They are also called as auto-global as they can be used inside a function as well. The arrays with the longs names such as $HTTP_SERVER_VARS, must be made global before they can be used in an array. This $HTTP_SERVER_VARS check your php.ini setting for long arrays.

An index is a object which is used to improve performance during retrieval of records.

CREATE [UNIQUE] INDEX index_name 

ON employee[emp_id, emp_name,dept_id]

[COMPUTE STATISTICS]

The UNIQUE keyword is used when combined values of the index should be unique.

The COMPUTE STATISTICS during the creation of index optimizes the plan of execution of the SQL statement and improves performance.

While allocating KSDS Datasets, free space is declared at regular intervals at the time of initial loading. This is done because this free space is utilized for keeping the data arranged in sequence physically, even though inserted randomly.

Visual basic can be used for server side scripting. A component designed with Visual basic will not have any user interface instead provides the functionality of Active X to other programs via COM. This form of technique allows server side functionality and add in module.

You must code EXEC CICS ASSIGN with the OPENID option.