Data Warehouse And Data Mining Flashcards
What is a data warehouse?
A decision making system which integrates data from multiple sources, organises and stores it for an organisation’s use.
What are the key properties of a data warehouse?
- Integrated: brings together data from different sources.
- Non-volatile: data warehouses only store data, not alter; they are not updated constantly.
- Subject-oriented: data warehouse revolve around important subjects of an organisation like customers, employees, sales.
- Time variance: data warehouses store historic data; they stored data accurately in particular points in time.
- Time variance: data is st
What is OLTP?
Online Transaction Processing System (Databases)
What is OLAP?
Online Analysis Processing System (Data warehouses)
Differences between Database (OLTP) and Warehouses (OLAP).
OLTP || OLAP
* Collection of interrelated data || Collection of information
* Contains data recently collected|| Contains historic data
* Transaction driven || Analysis driven
* Support day-to-day operations || Support strategic decisions
What is the main objective of data warehouses?
To integrate and store data from multiple sources
Benefits of data warehouses
- Keeps historic information
- Analyzes data from multiple sources
- Offers data backup sources
- Has high potential return
Types of data warehouses
- Centralised data warehouse
- Distributed data warehouse
What is a centralised data warehouse?
Data is stored in one place.
What is a distributed data warehouse?
Data is physically spread across various data warehouses which still communicate with one another.
Types of distributed warehouses.
- Homogeneous: data warehouses share the same operating system or platform.
- Heterogeneous: data warehouses have different operating systems or platforms
