 |
| Understanding Data Warehouse Database Modeling. |
1. What is meant by surrogate key in a data warehouse?
Used as a replacement or substitute for a descriptive primary key, allowing for better control , better structure, less storage space, more efficient indexing, and absolute surety of uniqueness.
2. What is meant by star schema?
A single fact table surrounded by a single hierarchical layer of dimensional tables, in a data warehouse database.
3. What is meant by snowflake schema?
A data warehouse, single fact table structure, with dimension tables in multiple layered hierarchies of dimensional tables.
4. Write the steps to build warehouse module?
The steps to build warehouse model are as follows:
1. Business process
2. Granularity
3. Identify and build dimensions
4. Build facts
05.What do you know by time dimension?
Used for temporal analysis in data warehouse. Time dimension table is used for time based data analysis. The result of this is that facts can be analyzed by month, quarter and year.
0 Comments