You have two databases with same size, then dow do you identify which is OLTP or OLAP?
Normalized model is OLTP, Denormalized model is OLAP
Need of Data warehouse?
1)To Analysis of data and history maintenance.
2)Companies require Strategic information to face the competition in market.
3)The Operation system are not designed for strategic information.
4)To maintain history of data for whole Organization and to have a single place where the entire data stored.
What is data warehousing and Explain Approaches?
Many companies follow either characteristic defined by W.H.Inmon or Sean kelly.
Subjected Oriented, Integrated, Non Volatile,Time Variant
b)Sean Kelly definition
Seperate, Available, Integrated,TimeStamped,Suject Oriented, Non Volatile, Accessible
There are two Approches
1.Top Down by Inmon
2.Bottom Up by Ralph kimbal
Inmon approach:Enterprise datawarehouse structured first and next Datamart created.(TopDown).
Ralph kimbal:Datamart designed first, later Datamarts to Datawarehouse designed.(BottomUp).
What are the responsibilities of a data warehouse consultant/professional?
The basic responsibility of a data warehouse consultant is to ‘publish the right data’.
Some of the other responsibilities of a data warehouse consultant are:
1. Understand the end users by their business area, job responsibilities, and computer
2. Find out the decisions the end users want to make with the help of the data warehouse.
3. Identify the ‘best’ users who will make effective decisions using the data warehouse
4. Find the potential new users and make them aware of the data warehouse.
5. Determining the grain of the data.
6. Make the end user screens and applications much simpler and more template driven.
What are fundamental stages of Data Warehousing?
a)Offline Operational Databases - Data warehouses in this initial stage are developed by simply copying the database of an operational system to an off-line server where the processing load of reporting does not impact on the operational system's performance.
b)Offline Data Warehouse - Data warehouses in this stage of evolution are updated on a regular time cycle (usually daily, weekly or monthly) from the operational systems and the data is stored in an integrated reporting-oriented data structure.
c)Real Time Data Warehouse - Data warehouses at this stage are updated on a transaction or event basis, every time an operational system performs a transaction (e.g an order or a delivery or a booking etc.)
d)Integrated Data Warehouse - Data warehouses at this stage are used to generate activity or transactions that are passed back into the operational systems for use in the daily activity of the organization.
What is Datamart Explain Types?
It is a specific Subject area or Functionality or Task.
It is Designed to facilitate end user Analysis.
Wrong Answer-- It is a subset of warehouse
Types of Datamarts
Dependent, Independent, Logical.
Dependent: Created from Datawarehouse as a seperate physical store.
Independent :Created directly from operational systems to a seperate physical store.
Logical: Exists as a subset of existing Datawarehouse.