Chapter 2: Data Warehousing

A subset that is created directly from a data warehouse.

Dependent data mart

A retrieval-based system that supports high-volume query access

Dimensional Modeling

A small data warehouse designed for a strategic business unit or a dept.

Independent data mart

This approach emphasizes top-down development, employing established db development methodologies and tools, such as ERD

Inmon model, EDW approach

"Plan big, build small" approach, bottom-up. It is a scaled down DW that focuses on requests from specific depts

Kimball model, Data Mart approach

Oper marts are an operational data mart.

True

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

Data Warehouse

Integration that comprises 3 major processes: data access, data federation, and change capture.

Data integration

A departmental small-scale Data Warehouse that stores only limited/relevant data.

Data mart

Major components of the data warehousing process:

Data sources, ETL, data loading, comprehensive database, metadata, middleware tools

A technology that provides a vehicle for pushing data from source systems into a data warehouse.

Enterprise application integration (EAI)

A data warehouse for the enterprise

Enterprise data warehouse (EDW)

An evolving tool space that promises real-time data integration from a variety of sources, such as relational or multidimensional databases, web services, etc

Enterprise information integration (EII)

Data about data. In DW, it describes the contents and the manner of its acquisition and use.

Metadata

_ tools enable access to data warehouse.

Middleware

OLAP implemented via a specialized multidimensional database (or data store) that summarizes transactions into multidimensional views ahead of time

Multidimensional OLAP (MOLAP)

The ability to organize, present, and analyze data by several dimensions, such as sales by region, by product, by salesperson, and by time (four dimensions).

Multidimensionality

A type of database often used as an interim area for a data warehouse.

Operational data stores (ODS)

The implementation of an OLAP database on top of an existing relational database

Relational OLAP (ROLAP)

Logical arrangement of tables in a multidimensional db in such a way that the ERD resembles a snowflake.

Snowflake Schema

The most commonly used and the simplest style of dimensional modeling.

Star Schema

A star schema contains a central fact table surrounded by and connected to several _.

dimensional tables

The ETL process consists of

extraction (reading data from one or more dbs), transformation (converting extracted data form one or more dbs), and load (putting the data into the DW)

The data warehouse is a collection of _, _ databases designed to support DSS functions, where each using of data is _ and relevant to some moment in time.

integrated, subject-oriented, non-volatile

OLAP Operations:

slice, dice, drill down/up, roll up, pivot