ISDS 2001 Test 2 Chapter 2

A physical repository where relational data are specially organized to provide enterprise-wide, cleansed data in a standardized format

"The data warehouse is a collection of integrated, subject-oriented databases designed to support DDS functions, where each unit of data is non-volatile and relevant to some moment in time"

To provide the single version of the truth

• Subject-oriented
• Integrated
• Time-variant
• Nonvolatile

Data are organized by topics, such as sales, products, customers, etc. Best for providing a more comprehensive view of the organization; not only how a business is operating, but why.

Data from different sources are stored in a consisten format. Also clarity is obtained in unit of measures, naming/labeling of attributes, etc. (The assumption is the datat warehouse is totally integrated.)

Provides data at various points in time (daily, weekly, monthly, quaterly, annually - historic and current data so as to analyze trends, deviations, compare and forcast outcomes, etc.) Every data warehouse should have a time variable.

i.e. LSU enrollement, retention, graduation data

• Data Mart
• Operational Data Stores (ODS)
• Enterprise data warehouses (EDW)

a subset of a data warehouse, usually consisting of a single subject area (marketing, sales, customer satisfaction inventory, production, etc.)

• Dependent Data Mart
• Independent Data Mart

Created directly from the data warehouse. This ensures that the user is using/viewing the same data available at all other users. EDW must be constructed first.

A small warehouse designed for a department or strategic business unit (SBU). Its source is not an EDW

A type of database often used as an interim (or staging) area for a data warehouse, especially for customer information files (CIF). Data are updated frequently through the course of business operations as opposed to the static contents of a data warehouse. (short-term memory)

A large-scale data warehouse that is used across the enterprise/company for decision support. Being large-scaled, the EDW integrates data in standard format from many sources. (Direct TV and Enterprise use EDW)

• An ODS (Operational Data Store) is the database from which a business operates on an ongoing basis.
• Both an EDW and a Data Mart are data warehouses. An EDW (Enterprise Data Warehouse) is an all-encompanssing DW that covers all subject areas of interest to the entire organization. A data mart is a smaller DW designed around one problem, organizational function, topic, or other suitable focus area

is a subset of a data warehouse, typically consisting of a single subject area (smaller and focusing on a particular subject or department). A data mart can be either dependent or independent.

a subset that is created directly from the data warehouse

it has the advantages of using a consistent data model and providing quality data

a small warehouse designed for a strategic business unit or department, but its source is not an EDW

This type of database is often used as an interim staging area for a data warehouse.

An ODS is similar to short-term memory in that it stores only very recent information

a large-scale data warehouse that is used across the enterprise for decision support.

The large scale nature provides integration of data from many sources into a standard format for effective BI and decision support applications

• Data about Data
• descirbes the contents of a data warehouse, its structure (such as a field name, data type, default value, length), meaning, syntax and the manner of its use.

Syntactic Metadata

Structural Metadata

Semantic Metadata

Data describing the syntax of data

ex. "Dublin Core" may be expressed in plain text, HTML or XML

Data describing the structure of the data

ex. field name, data type, length, table relationships

Data describing the meaning of the data

ex. a webpage may include metadata specifying what language it is written in

• 
• 1. Database Server (data acquisition software - backend)
• 2. The data warehouse that contains the data & software (application server)
• 3. Client (front-end) software that allows users to access and analyze data from the warehouse (Client Workstation)

• 
• 1. Application and database server
• 2. Client Workstation