Interview Questions

A network in which there are multiple network links between computers to provide multiple paths for data to travel.

Open Market Operations (OMO) refer to the buying and selling of government securities in the open market in order to expand or contract the amount of money in the banking system.

DB2 use the multiple indexes to satisfy multiple predicates in a SELECT statement that are joined by an AND or OR.

main() method is called by the JVM even before the instantiation of the class, hence it is declared as static.

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.

Smart money is a term used for credit card.

In a correlated query, the outer query is related to the inner query. This means one or more columns in the outer query are referenced. It’s used when the outer queries value is being used by inner query. For example, we need to find which employee had more perks in the current month than they did in the previous month. The correlated subquery is executed for each row of perks information in the parent query to first determine what the perks were for each employee in the previous month. This data, in turn, is compared to perks for each employee in the current month, and only those employees whose perks in the current month were greater that their previous month's perks are returned.

The simplest DB2 index is the B-tree and the B-tree's top page is called the root page. The root page entries represent the upper range limits of the index and are referenced first in a search.