daer my franz....

ak dedecate pic nie tuk kowg smua..

nie laa yg ak wt ms ct dlu...

u all r always in myheart......

recome back

dh lm x blogging....
rs cm nk stsrt blik laa...
tp nk start ngn cter per ea??

why???

why i choose this topic???

• it is easy 2 understand
• I read this topic 4 my quiz while I write this articel.
• save time rite??

my roomet said that iL is my fav. subject,,really???
maybe,,4 me iL is not too diffcult,but it need consistant reading...
4 me this is very though work coz i dont love reading....
how bout you all???

Data Warehousing

A data warehouse is a repository of an organization's electronically stored data. Data warehouses are designed to facilitate reporting and analysis.

The basic character of data warehouse are :
Organized by business dimension or subject. Data organized by subject and contain information relevant for decision support and data analysis.
Consistent. Data in different database may be encoded differently.all data must be encoded in a consistent manner.
Historical. The data are kept for many years can be used for identifying trends, forecasting, and making comparisons over the time.
Nonvolatile. Data are not updated after they are entered inro dat warehouse.
Use only online analytical processing. Organization data base are oriented toward handling transaction using online transaction processing(OLTP)
Multidimensional. A common representation for this multidimensional structure is the data cube.
Relationship with relational database.

1. Inmon, W.H. Tech Topic: What is a Data Warehouse? Prism Solutions. Volume 1. 1995.
2. Yang, Jun. WareHouse Information Prototype at Stanford (WHIPS). Stanford University. July 7, 1998.
3. R. Kelly Rainer Jr. efraim turban. Introduction to information systems 2nd edition. Asia. John Wiley & Son Inc
4. Data mart. Wikipedia the free encyclopedia. Available at http://en.wikipedia.org/wiki/Data_warehouse

Benefits and Drawbacks of data warehousing

benefits that a data warehouse provides are as follows:

A data warehouse provides a common data model for all data of interest regardless of the data's source. This makes it easier to report and analyze information than it would be if multiple data models were used to retrieve information such as sales invoices, order receipts, general ledger charges, etc.

• Prior to loading data into the data warehouse, inconsistencies are identified and resolved. This greatly simplifies reporting and analysis.
• Information in the data warehouse is under the control of data warehouse users so that, even if the source system data is purged over time, the information in the warehouse can be stored safely for extended periods of time.
• Because they are separate from operational systems, data warehouses provide retrieval of data without slowing down operational systems.
• Data warehouses facilitate decision support system applications such as trend reports (e.g., the items with the most sales in a particular area within the last two years), exception reports, and reports that show actual performance versus goals.
• Data warehouses can work in conjunction with and, hence, enhance the value of operational business applications, notably customers relationship management (CRM) system

There are also disadvantages to using a data warehouse. Some of them are:

• Over their life, data warehouses can have high costs. The data warehouse is usually not static. Maintenance costs are high.
• Data warehouses can get outdated relatively quickly. There is a cost of delivering suboptimal information to the organization.
• There is often a fine line between data warehouses and operational systems. Duplicate, expensive functionality may be developed. Or, functionality may be developed in the data warehouse that, in retrospect, should have been developed in the operational systems and vice versa
  

1. Caldeira, C. "Data Warehousing - Conceitos e Modelos". Edições Sílabo. 2008. ISBN 978-972-618-479-9
2. DMReview Magazine Glossary. Data Management Review and SourceMedia, Inc. 2008.
3. R. Kelly Rainer Jr. efraim turban. Introduction to information systems 2nd edition. Asia. John Wiley & Son Inc
4. Data mart. Wikipedia the free encyclopedia. Available at http://en.wikipedia.org/wiki/Data_warehouse

Data Mart

A data mart is a subset of an organizational data store, usually oriented to a specific purpose or major data subject, that may be distributed to support business needs.Data marts are analytical data stores designed to focus on specific business functions for a specific community within an organization. Data marts are often derived from subsets of data in a data warehouse though in the bottom-up data warehouse design methodology the data warehouse is created from the union of organizational data marts.

Reasons for creating a data mart

• Easy access to frequently needed data
• Creates collective view by a group of users
• Improves end-user response time
• Ease of creation
• Lower cost than implementing a full data warehouse
• Potential users are more clearly defined than in a full data warehouse

1. R. Kelly Rainer Jr. efraim turban. Introduction to information systems 2^nd edition. Asia. John Wiley & Son Inc
2. Data mart. Wikipedia the free encyclopedia. Available at http://en.wikipedia.org/wiki/Data_mart

zamilaty

friends make me happy,

without them my world is dull

do you ever hear bout this...."without girls i unhappy,without boys i feel lonely"....

but for me whether boy or girl if they are my friend i'm always happy with them..

that is why friendship never ending