Practice Data Warehousing Questions and Answers

• Which of these is NOT an ensemble method?
• A star schema in a data warehouse consists of:
• ETL stands for:
• Which OLAP operation allows users to view data at different levels of granularity?
• A snowflake schema is different from a star schema because:
• Metadata in data warehousing refers to:
• Which of the following is a real-time data warehouse application?
• Which OLAP operation involves focusing on a subset of dimensions (e.g., region=‘Asia’)?
• In a star schema, what is the main advantage of using surrogate keys in fact tables?
• Fact constellation schema is best described as:
• In OLAP, “Slice and Dice” means:
• A Fact Constellation Schema is also called:
• Surrogate keys are used in data warehouses because:
• Which of the following stores historical data for analysis?
• What is a data mart?
• Which OLAP operation summarizes data along a dimension?
• Which type of OLAP allows analysis of multidimensional data stored in relational databases?
• A data cube allows analysis by:
• ETL stands for:
• Which of these is not a typical data warehouse characteristic?
• Which schema uses multiple fact tables sharing dimension tables?
• Data warehouse metadata primarily describes:
• Which SQL clause is used to filter records after aggregation?
• Which SQL function returns the total number of rows in a table?
• What is the result of SELECT COALESCE(NULL, NULL, 5, 10);?
• Which SQL keyword is used to combine results from two queries and remove duplicates?
• Which clause is used to sort the results in SQL?
• In a data warehouse, a fact table typically contains:
• Which OLAP operation rotates the data axes to provide an alternative presentation?
• What is the main purpose of a data mart?
• Which type of schema normalizes dimension tables to reduce redundancy?
• ETL stands for:
• Which type of schema uses a central fact table connected to dimension tables?
• Which of the following is a key process in ETL?
• Which OLAP operation allows drilling down into more detailed data?
• Which type of data warehouse is focused on specific business lines or departments?
• Which type of OLAP allows operations on pre-aggregated data cubes?
• In a data warehouse, which type of table stores quantitative data for analysis?
• Which of the following is used to maintain information about the structure of a data warehouse?
• Which operation in OLAP allows selecting a single dimension from a cube?