SHORT

Hai people..

Its time to update my blog..  

CHAPTER 7

(STORING ORGANIZATIONAL INFORMATION - DATABASES) 

• A placed to kept and stored the organizational information for the program to consult it to answer queries that can be used to make decisions.
• A collection of records or pieces of information.

• Maintain information about various types of objects (inventory), events (transactions), people (employees), and a place (warehouse). 

SCHEMA is a structural description of the type of facts held in that database. It describes the objects that are represented in the database and the relationships among them.

DATABASE MODEL/DATA MODELS is a modulling the database structure are a number of different ways of organizing a schema. 

RELATIONAL DATABASE MODEL (COMMONLY USED)

• Represents all information in the form of multiple related tables each consisting of rows and columns. (two-dimensional table)
• Represents relationships by the use of values common to more than one table.

ENTITIES is a person, place, thing, transaction, or event about which information is stored.

ATTRIBUTES is a characteristics or properties of an entity class.

PRIMARY KEY is a field or group of fields that uniquely identifies a given entity in a table. Its provide a way of distinguishing each entity in a table.

FOREIGN KEY is a primary key of one table that appears as an attributes in another table and acts to provide a logical relationship between the two tables.

ADVANTAGES:-

• Increased flexibility.
• Increased scalability and performance.
• Reduced information redundancy.
• Increased information integrity (quality).
• Increased information security.

HIERARCHICAL DATABASE MODEL

• Information is organized into a tree-like structure that allow repeating information using parent or child relationship that it cannot have too many relationship.
• Widely used in the first mainframe DBMS.
• Cannot be used to relate to structures that exists in the real world.

NETWORK DATABASE MODEL

• A flexible way of representing objects and their relationships.
• Forming a lattice structure that allows each records to have multiple parent and child records.

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CHAPTER 8

(ACCESSING ORGANIZATIONAL INFORMATION - DATA WAREHOUSE) 

DIFFERENCES BETWEEN :-

DATA WAREHOUSING	DATABASE
Constitute entire information base for all time	Constitute real time information
Supports decision making and business intelligence	Does not support decision making and business intelligence
It is about how to run the business	It is used to running the business

 Data warehouse is a single, complete and consistent store of data obtained from a variety of different sources made available  to end users in a what they can understand and use in a business context. 

Data warehousing is a process of transforming data into information and making it available to users in a timely enough manner to make a difference.

 

Subject Oriented is a data that gives information about a particular subject instead of about a company's ongoing operations.

Integrated is  a data that is gathered into the data warehouse from a variety of sources and merged into a coherent whole.

Time-variant is defined as all data in a data warehouse is identified with a particular time period.

Non-volatile means that data is stable in a data warehouse  even there is more data is added but data is never removed. This enables management to gain a consistent picture of the business.

HISTORY OF DATA WAREHOUSING :-
Late 1980s - IBM researchers Barry Devlin and Paul Murphy developed the "business data warehouse".
1960s - General Mills and Dartmouth College, in a joint research project, develop the terms dimensions and facts.
1970s - ACNielsen and IRI provide dimensional data marts for retail sales.
1983 - Tera data introduces a database management system specifically      designed for decision support.
1988 - Barry Devlin and Paul Murphy publish the article An architecture for a business and information systems in IBM Systems Journal where they introduce the term "business data warehouse".

 

Data Mining is the process of analyzing data to extract information not offered by the raw data alone.

Data Mining Tools is a variety of techniques to finds patterns and relationships in large volume of information and infer rules from them that predict future behavior and guide decisions making.

BUSINESS INTELLIGENCE

• Applications and technologies that are used to gather, provide access to, and analyze data and information to support decision making efforts.

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 see you again.. :)