Passed Exam Today 1z0-071

For displaying unique promotion costs in each promotion category from the PROMOTIONS table:

• A. SELECT DISTINCT promo_category, promo_cost FROM promotions ORDER BY 1: This query correctly retrieves unique combinations of promo_category and promo_cost, sorting the results based on the promo_category.
• D. SELECT DISTINCT promo_category || ' has ' || promo_cost AS COSTS FROM promotions ORDER BY 1: This query correctly combines the category and cost into a single string for each unique combination, using string concatenation and the DISTINCT keyword to ensure uniqueness, sorting by the concatenated string.

Incorrect options:

• B: This does not ensure that the combinations of promo_cost and promo_category are unique because DISTINCT was not specified for both columns together.
• C: The syntax is incorrect; DISTINCT cannot be applied to a single column partway through a SELECT clause.
• E: This is syntactically incorrect as DISTINCT cannot be used twice in the way shown; it must apply to all columns if used at the beginning of a SELECT statement.

C. True, the names of the columns in each SELECT statement of an INTERSECT query do not need to match, as long as the data types and order of the columns correspond.D. True, the INTERSECT operator returns only the rows that are common to both SELECT statements, effectively acting as a set intersection of the results from both queries.

References:

• Oracle documentation on INTERSECT operator: Oracle Database SQL Language Reference
• Detailed behavior of INTERSECT: Oracle Compound Queries

B: True. The REFERENCES privilege can be granted on specific columns within a table. This is necessary when a user needs to define foreign key constraints that reference those particular columns.

C: True. The UPDATE privilege can be granted on specific columns, allowing users to update only designated columns within a table. This is useful for restricting write access to sensitive or critical data within a table.

F: True. The INSERT privilege can also be granted on specific columns, meaning a user can be permitted to insert data into only certain columns of a table. This helps in maintaining data integrity and controlling access to data fields based on user roles.

The TRUNCATE TABLE command in Oracle SQL is used to quickly delete all rows from a table:

• Option A:
• Option D:

Options B, C, E, and F are incorrect because:

• Option B: TRUNCATE does not drop triggers; it only removes all rows.
• Option C: Flashback Table cannot be used after a TRUNCATE because TRUNCATE is a DDL operation that does not generate undo data for flashback.
• Option E: A ROLLBACK cannot be used after a TRUNCATE because TRUNCATE is a DDL command that implicitly commits.
• Option F: TRUNCATE may deallocate the space used by the table, depending on the database version and specific options used with the TRUNCATE command.