Data Mart....

Well...
as i explained about the definitions of DWH., Now am going to tell you about a word "DATA MART"

We know that DWH is a also Database which will be designed with the information from Multiple
Operational Databases, Data Mart is a Sub-Set of DWH.
DataMart is used to maintain the business needful data of Department specific business users (or) Middle Management.
A DataMart is known as High Performance Query Structures(HPQS).
reason: Since the DataMart is a sub-set of a DWH database, the processing time for Execution of Query is very less as a DWH is a Huge Database.

Few differences btw DATA MART & DATA WARE HOUSING...

DM : Defines a Single subject.
DWH: Defines Integration of Multiple subjects.

DM : Designed for Middle Management Access.
DWH: Designed for Top Management Access.

DM : Stores dept. specific business information.
DWH: Used to store Enterprise-wise Business info.


There are two types of DataMarts...
(i) Dependent Data Mart.
(ii) Independent Data Mart.

To know these two types, we need to know two DWH approaches...

Will tell you in detail in my next post., as a bit tired for today.
I don't want this Blog to be IDLE for a while, so came here now with this topic...

Catch you soon... till then, keep rocking.

Enjoy The Joy.....

Definitions of DataWareHousing....

Yeah... i used the term "Definitions"... there is a reason.

Mostly for every technology or domain, you can find only ONE as FATHER of that particular technology.
Coming to DataWareHousing,for this Technology... Two Fathers are there.

-->Ralph Kimball
-->W H Inmon

Why it has two technocrats? whats the reason behind it?

Yeah, The Technology is same but the WAY of APPROACH defined by one to other is deifferent.


*According to RALPH KIMBALL...
A DWH is a Relational database, which is specially designed for Business Analysis purpose, but not for Business Transaction Processing.
A DWH is designed to support Decision Making Process. (Also called as DSS(Decision Spporting System)
Only Business Managers need a DWH for Analysis of the summery of Business.

*According to W H Inmon...
A DWH is
-> Time Variant
-> Non-Volatile
-> Integrated
-> Subject Oriented

First DWH is invented by WH Inmon in 1987


Time Variant: Simple example for this one is in analysis of a company performancy, you can observe "Daily", " Weekly", "Monthly", "Quarterly"... and so on... so this is called Time variant. A DWH supports Time Variant to analyze,
where as Operational database is not much compatible.

Non-Volatile: Yeah, once data entered or a record Inserted, it is not subjected to change. Thats why called Non-Volatile. Where as in Operational Database, record will be modified.

Integrated: We can Integrated multiple databases and also multiple types of Data Sources in ETL Applications. (OACLE, SQL, DB2.....)

Subject Oriented: It can be called as Subject Oriented because all the Data elements are linked together and relevant to each other....

okay, in my next post... will go through "DATA MART"..

Keep rocking... Enjoy the Joy

What? - Who? - Why?

Hmm.., don't get confused....

What? - Who? - Why? means..

What is DataWareHousing?
Who needs it?
Why they need it?

Let me answer for

WHAT?
A DataWareHousing is a Database, which is Specially designed to store the information of summery of Business.

WHO?
Who needs the summery?
Lets assume that you own a Business, and you have many employees.
The low level executives maintains the detailed information, and High level executives go through the Summery for Analysis of Business. (Like Daily, Weekly, Monthly, Quarterly... and so on.....)
As a Owner or CEO or Chairman, you need not go through detailed information.
So What ever Summery information we are storing, will be useful for Middle Level Management and Top Level Management.

Why?
Yeah, your next question is WHY?
As you have already a Database which consists detailed information, why won't you give desired reports or summery from there itself?

Here is a Simple answer...
You can call a DataWareHousing is DSS i.e Decision Supporting System.
That means, you are maintaining a individual database only to take Decision by analyzing the Business. Like Current Daily Revenue, Current Weekly Revenue, Last month Daily Revenue, Current Weekly.... so that you can analyze whether your business is growing or falling. and also you can take Actions to Improve Business. That's why DataWareHousing is DSS.

But why need to build seperate database?
Because in Current (regular transaction) data consists detailed information, it will be Time consuming to retrieve information from the existing database.
And also it maintains only one Branch transactions (Assume you have two branches in DilshukhNagar and KukatPalli)., in DataWareHousing, you can Integrate Multiple Branches Business Data to Single.


Note: Here Current database is called as Operational Database. That means, from Operational Database(s) we are developing a (Data)WareHouse.

Note: You will see "Business" term commonly. The thing is a DataWareHouse is a tool for BI (Business Intelligence). So what ever we deal in DataWareHousing, is all about a Business.

Well.., thats all in for this Day.

Keep Rocking....

Welcome...

Hi all..,
This is my new blog next to www.joy360degrees.blogspot.com.
In this Blog, i wish to share what ever i know about DataWareHousing-Informatica.
Of-course, i am at learning stage, still i just want to express what am understanding about this Technology.

So visit it, read me, and also share your comments...


Thanks & Regards,
Udaykanth.S