Question
In a star schema, what is the main advantage of using
surrogate keys in fact tables?Solution
Surrogate keys are artificial keys used in dimensions to avoid natural key duplication, speed joins, and handle SCDs cleanly.
What is a data mart?
Which SQL query will correctly calculate the average salary of employees in each department and group them by department in a table named 'employees'?
Which analytics type is focused on predicting future outcomes?
Which of the following is a key process in ETL?
Which OLAP operation summarizes data along a dimension?
A data cube allows analysis by:
In the context of a relational database, which of the following is NOT a characteristic of a candidate key ?
A snowflake schema is different from a star schema because:
ETL stands for:
What does "drill-down" operation in OLAP do?