MIS Chapter 3.4
What are some of the characteristics of organizations that use data warehousing?
1) End users need to access large amounts of data, 2) Operational data are stored in diff systems, 3) Organization employs an info-based approach to mgmt, 4) Org serves large, diverse customer base, 5) Same data are represented differently in diff systems, etc.
What are the benefits of consolidating data marts into a data warhouse?
1) Minimize investment/risk of failure of a large information systems, 2) Compliance, 3) Going green
The 9 characteristics of a data warehouse
1) Organization, 2) Consistency, 3) Time variant, 4) Nonvolatile, 5) Relational, 6) Client/Server, 7) Web-based, 8) Integration, 9) Real-time (OCTNRCWIR)
What are 2 reasons for creating a data warehouse as a separate data store?
1) The performance of a separate data store is better b/c it is not waiting for processsing time. 2) Modeling a database that can be used for both operational and analytical purposes can be difficult.
Data marts
Lower cost, scaled-down version of a data warehouse. Designed for a strategic business unit (SBU) or a single department.
Name one similarity and one difference b/w data warehouse and a regular database
Similarity: Both have data tables (files), primary and other keys, and query capabilities. Difference: Databases are designed and optimized to STORE data, whereas data warehouses are designed and optimized to RESPOND to analysis q's that are critical for a business.
Compliance
Storing integrated data in an EDW (enterprise DW) makes it easier for the company to control which people can access and use sensitive financial data.
Two-tier
a common architecture for data warehousing
Three-tier
data from the warehouse are processed twice and deposited in an additional multidimensional database or replicated in data marts
Multidimensional database
data warehouse that can be based on a multidimensional model; views data in the form of a data cube. Ex - a product's 3D data cube could show 3 measures: item name, qty sold, and geographical region.
Operational data store
database for transaction processing systems (TPS) that uses data warehouse concepts to provide clean data. Used for short-term decisions involving mission-critical applications rather than for the medium- and long-term decisions associated with reg data warehouse. These decisions require current info.
Multidimensional database
database in which data is organized for easy multidimensional analysis and presentation
Online Analytical Processing (OLAP) systems
Data warehouses are designed as these, meaning data can be queried and analyzed much more efficiently than OLTP app databases.
Why move data from database to data warehouse?
Databases are volatile b/c of amt of info being dealt with; volatility makes data analysis very difficutlt; so we move it data warehouses (becomes read only data) through ETL (extract, tranform, load).
Online Transaction Processing (OLTP) systems
Databases in which every transaction is recorded quickly. Ex - financial transactions from ATMs
Data center
newer facilities containing mission-critical ISs and components that deliver data and IT services to the enterprise. They integrate networks, computer systems, and storage devices.
