Slowly ChangingDimensions (SCD) — Learn free

Self-check

Questions 1–10 of 10

1. In which concept are Slowly Changing Dimensions (SCD) used?
Question 1A. Network securityB. Data WarehousingC. Web page designD. Video streamingE. Country code standards
2. What are the two types of schema found in a dimensional Data Warehouse or Data Mart?
Question 2A. Star and Snowflake schemasB. Landing and Staging schemasC. Public and Private schemasD. Relational and Document schemasE. Primary and Secondary schemas
3. What does a Fact table keep?
Question 3A. Descriptions of regions and productsB. The list of database users and their permissionsC. The transaction's lowest level of data, such as sales numbers, clicks or searchesD. The history of schema changesE. Metadata about each column's data type
4. How is a Fact table mainly loaded?
Question 4A. In overwrite mode, replacing all rows each nightB. In delete mode, removing old rows firstC. In read-only mode with no new rowsD. In append mode, meaning rows always get insertedE. In merge mode, updating rows in place
5. Which of these is an example of a Dimension?
Question 5A. The number of clicks on a portalB. The daily sales amountC. The count of Google searchesD. The transaction timestamp value in a fact rowE. Region, by which sales can be analysed
6. How does the frequency of new rows in a Dimension table compare with a Fact table?
Question 6A. Dimension rows arrive at a very low frequency compared with the fast-moving Fact tableB. Dimension rows arrive far more often than Fact rowsC. Both tables receive rows at exactly the same rateD. Dimension tables never receive any rows after the first loadE. Fact tables receive rows only once a year
7. If a product code changed from 001 to 002, then 003, then 004, what would SCD Type 1 keep?
Question 7A. 001 onlyB. 004 onlyC. 001 and 004D. 001, 002, 003 and 004E. 002 and 003
8. Which SCD type keeps a complete history of every change to a dimension?
Question 8A. SCD 1B. SCD 0C. SCD 2D. SCD 3E. SCD 4
9. If a product code changed from 001 to 002, then 003, then 004, what would SCD Type 3 keep?
Question 9A. 004 onlyB. All four valuesC. 002 and 003 onlyD. 001 and 004 onlyE. Nothing, since SCD 3 discards history
10. Why is a Dimension such as Products a candidate for Slowly Changing Dimension handling?
Question 10A. Because product data is loaded in append mode like a factB. Because products are never analysed in reportsC. Because product tables receive thousands of rows per secondD. Because product data is stored outside the warehouseE. Because a company can add products over time and the attributes of a product can change in future