Data Warehousing Glossary
ETL: Stands for Extraction, Transformation, and Loading. The movement of data from one area to another.
Fact Table: A type of table in the dimensional model. A fact table typically includes two types of columns: fact columns and foreign keys to the dimensions.
Hierarchy: A hierarchy defines the navigating path for drilling up and drilling down. All attributes in a hierarchy belong to the same dimension.
Metadata: Data about data. For example, the number of tables in the database is a type of metadata.
Metric: A measured value. For example, "Total Sales" is a metric.
MOLAP: Multidimensional OLAP. MOLAP systems store data in the multidimensional cubes.
OLAP: On-Line Analytical Processing. OLAP should be designed to provide end users a quick way of slicing and dicing the data.
ROLAP: Relational OLAP. ROLAP systems store data in the relational database.
Snowflake Schema: A common form of dimensional model. In a snowflake schema, different hierarchies in a dimension can be extended into their own dimensional tables. Therefore, a dimension can have more than a single dimension table.
Star Schema: A common form of dimensional model. In a star schema, each dimension is represented by a single dimension table.