Data Warehousing Flashcards
1
Q
Data Warehouse
A
- Support database maintained separately from the operational database
- Consolidated, historical data for analysis
- Requires only data loading and data access
2
Q
Characteristics of a Data Warehouse
A
- Subject-oriented
- Integrated
- Time-variant
- Nonvolatile
3
Q
Populating a Data Warehouse
A
- Select data important for analysis
- Clear incomplete or inconsistent tuples
- Summarize values as necessary
4
Q
OLAP vs OLTP
A
- OLAP: on-line analytical processing
- OLTP: on-line transactional processing
5
Q
Applications of Data Warehouses
A
- Information processing
- Analytical processing
- Data mining
6
Q
Data Cube
A
- Multidimensional data model that provides summarizations for all subsets of dimensions
7
Q
Cuboids
A
- Summarizations along different dimensions of the data cube
8
Q
Base Cuboid
A
- The most detailed part of the data cube
9
Q
Apex Cuboid
A
- The highest level of summarization in the data cube
10
Q
Star Schema
A
- Consists of a central fact table connected to a set of dimension tables
11
Q
Snowflake Schema
A
- A refinement of star schema where some dimensional hierarchy is normalized
12
Q
Constellation Schema
A
- A collection of star schemas (multiple fact tables)
13
Q
Lattice
A
- A graph showing relationships between cuboids
14
Q
OLAP Slice
A
- Perform a selection on one dimension
15
Q
OLAP Dice
A
- Perform a selection on two or more dimensions
