Top 10 Data Warehouse Interview Questions & Answers
1)What is Data Warehousing?
The term that has come to distinguish this new technology is data warehousing.Data warehousing has grown out of repeated attempts by various researchers and organizations to provide their organizations with supple,effectual and efficient means of getting at the sets of data that have come to represent one of the organization’s most critical and valuable assets.
2)What is Data Redundancy?
There are three important levels of data redundancy that venture should think about data warehouse options:
a)Virtual or point-to-point data warehouses
b)Central data warehouses
c)Distributed data warehouse
3)what does OLAP stands for?
OLAP stands for Online Analytical Processing.It is a system that gathers,manages and processes multi-dimensional data for interpretation and management.
4)what does OLTP stands for?
OLTP stands for Online Transaction Processing.It is a system that rectifies the data whenever it received,to a large number of simultaneous users.
5)What are the types of OLAP servers?
d)Specialized SQL Servers
6)What is a data cube and how does it help?
A data cube is nothing but a multidimensional database which is an enhance version for data warehouse and OLAP applications.The query language that is used in the cube is different from the query language used in the traditional databases.
7)Define Warehouse Management system?
The warehouse management system is defined as it is a software and procedure that allows corporations to control and manage warehouse operations from the goods or materials enter a warehouse until they move out.Actions in a warehouse include inventory management ,picking, processing and auditing.
8) What are the important responsibilities of warehouse manager?
The important responsibilities of warehouse manager are as follows:
a) It performs integrity and consistency modifications
b) Frequently created indexes and also reforms where it is necessary
c) Grouping of the data based on the requirement from the data pool
d) Frequent backups
e) Involve in preparing data models as per the requirements from the project teams
9) What is normalization?
The term normalization is also known as Database Normalization.This is a process of rescheduling or organizing the columns and the tables that are associated in a relational database. by this process it reduces the data redundancy and also helps in improving the data integrity.
In short, normalization helps in reducing database design and the same time makes it easy while retrieving the data.
10)What are the characteristics of a data warehouse?
The important characteristics of a data warehouse are as follows:
a) The part of data can be De-normalized so that it can be simplified and improve the performance of the same.
b) A large amount of historical data is stored and used whenever it is needed.
c) A lot of queries are involved where lot of data is also retrieved based on the queries
d) The data load is controlled
e) Ad hoc queries and planned queries are very common when it comes to data extraction.