Materialized View — Learn free

Self-check

Questions 1–10 of 10

1. What is a materialised view?
Question 1A. A virtual table that fetches data on every queryB. A database object that physically stores the output of a queryC. A temporary table dropped at the end of a sessionD. An index built on a regular viewE. A file exported from a table
2. How does a materialised view differ from a regular view?
Question 2A. A materialised view cannot be queried with SELECTB. A materialised view is always smallerC. A materialised view physically stores the data, whereas a regular view is a virtual table derived from a SELECT queryD. A regular view stores data but a materialised view does notE. A materialised view cannot join multiple tables
3. What does a materialised view represent in terms of timing?
Question 3A. Live data reflecting every change instantlyB. Data as it will be after the next scheduled loadC. A random sample of the underlying tablesD. A snapshot of the data at the time it was last refreshedE. Only the rows inserted since creation
4. Are materialised views automatically updated when the underlying data changes?
Question 4A. Yes, always in real timeB. Yes, but only for insertsC. Only if they contain an aggregateD. Yes, whenever a SELECT is run against themE. No, they typically need to be refreshed periodically
5. Which command updates a materialised view with the latest data from the underlying tables?
Question 5A. REFRESH MATERIALIZED VIEW EmployeeProfile;B. UPDATE MATERIALIZED VIEW EmployeeProfile;C. RELOAD VIEW EmployeeProfile;D. SYNC VIEW EmployeeProfile;E. REBUILD VIEW EmployeeProfile;
6. Why can materialised views significantly improve query performance?
Question 6A. They compress the underlying tablesB. They store precomputed results, reducing the need to perform complex calculations on the flyC. They lock the base tables during queriesD. They run queries on a separate serverE. They remove the need for indexes
7. For which scenario are materialised views described as particularly useful?
Question 7A. Real-time transaction processingB. Enforcing referential integrityC. Offline analysis on a specific snapshot of the data without querying the live databaseD. Storing unstructured documentsE. Managing user permissions
8. When are materialised views especially effective for aggregation and summary?
Question 8A. When the underlying data changes every secondB. When the tables have no primary keysC. When queries are run very rarelyD. When the underlying data changes infrequently compared to the frequency of queryingE. When the data is stored in external files
9. How might a regular view and a materialised view be used together in one application?
Question 9A. The materialised view enforces security while the regular view stores dataB. Both must always be refreshed at the same timeC. The regular view is used only for inserts and the materialised view for deletesD. The materialised view replaces the regular view entirelyE. A regular view for real-time querying and a materialised view for periodic reporting or analytical purposes
10. How is a materialised view queried once it has been created?
Question 10A. Just like any other table or view, for example SELECT * FROM EmployeeProfile WHERE Age > 25;B. Only through a stored procedureC. Only after it has been converted to a regular tableD. Through a special MATERIALIZED SELECT statementE. By reading its underlying data file directly