Chapter 8 Accessing Organizational Information – Data Warehouse

Data warehouse is a logical collection of information  that gathered from many 

different operational databases that supports business analysis activities and 

decision-making tasks.

The primary purpose of a data warehouse is to aggregate information throughout an organization into a single repository for decision-making purposes.

they also have a system that uses for fixed the incorrect or incomplete information which is Information cleansing or scrubbing.

that all my comment..thank you..:)

chapter 7 Storing Organizational Information - Databases

Information is stored in databases

–Database – maintains information about various types of objects (inventory), events (transactions), people (employees), and places (warehouses)

Database models include:

–Hierarchical database model – information is organized into a tree-like structure (using parent/child relationships) in such a way that it cannot have too many relationships

–Network database model – a flexible way of representing objects and their relationships

–Relational database model – stores information in the form of logically related two-dimensional tables

 Entities and Attributes

Entity – a person, place, thing, transaction, or event about which information is stored

–The rows in each table contain the entities

–In Figure 7.1 CUSTOMER includes Dave’s Sub Shop and Pizza Palace entities

Attributes (fields, columns) – characteristics or properties of an entity class

–The columns in each table contain the attributes

–In Figure 7.1 attributes for CUSTOMER include Customer ID, Customer Name, Contact Name

Chapter 6

The value of quality info have five common characteristics that shows the high quality info.
ACCURACY - it is mean are the values corrects like the name is spelled correctly or not.
COMPLETENESS - are any value is missing  like the address code ,state, city and others.
CONSISTENCY - is aggregate or summary info in agreement with detailed info? example, do all total fields equal the true total of the individuals fields.
UNIQUENESS - is each transaction,entity and event represented only once in the information? for example are there any duplicate customers .
TIMELINESS - is the info current with respect to the business requirement for example , is information updated weekly,hourly or daily....