The query uses TO_CHAR and NEXT_DAY functions to format and determine dates:

B. It returns the date for the first Monday of the next month: The function NEXT_DAY(LAST_DAY(SYSDATE), ' MON ' ) finds the next Monday after the last day of the current month, effectively giving the first Monday of the next month. The TO_CHAR formatting is used to return this in a readable format.

INVISIBLE indexes are a feature in Oracle Database 12c and later versions that allow an index to be maintained but not used by the optimizer unless explicitly hinted.

A. False. An INVISIBLE index still consumes storage space as it is maintained in the background.

B. False. There is no such restriction. You can create multiple INVISIBLE indexes on the same column list.

C. False. The optimizer can consider INVISIBLE indexes if they are hinted at in the query.

D. True. You can alter the visibility of an index using the ALTER INDEX command to make an INVISIBLE index VISIBLE.

E. True. Even though they are invisible to the optimizer by default, all DML operations such as INSERT, UPDATE, and DELETE continue to maintain the index as they would with a VISIBLE index.

In Oracle SQL, when using the set operators like MINUS, the number of columns and their data types in the SELECT statements must match in sequence.

A. This query will not execute successfully because the SELECT * FROM bricks_stage will return all columns from the BRICKS_STAGE table, which are WEIGHT, SHAPE, and COLOR, but the first SELECT statement specifies only SHAPE and COLOR. The order and number of columns must match.

B. This query will not execute successfully. The SELECT statements have a different number of columns, and the data types of the columns in the same positions do not match between the two queries. The first column in the first SELECT is SHAPE (VARCHAR2), and in the second SELECT, it is WEIGHT (NUMBER).

C. This query will execute successfully. The SELECT * from both tables will ensure that the number of columns and their data types are the same, as SELECT * selects all columns from the table. As long as the two tables have the same column order and data types for those columns, the query will execute.

D. This query will not execute successfully. Even though the columns are of the same data types, their order in the SELECT statements must match for the set operator to work. The order of SHAPE and COLOR is switched between the two queries.

E. This query will not execute successfully. The number of columns in the SELECT statements is the same, but their data types do not match between the two queries. BRICK_ID (NUMBER) in the first query does not match WEIGHT (NUMBER) in the second, and SHAPE (VARCHAR2) does not match COLOR (VARCHAR2).

References:

Oracle Database SQL Language Reference, 12c Release 1 (12.1): " Combining Queries with Set Operators "

Oracle Database SQL Language Reference, 12c Release 1 (12.1): " MINUS "

When you use the INTERVAL literal for months, the result is displayed in years and months if the total number of months exceeds 12.

In the query given:

SELECT INTERVAL ' 100 ' MONTH DURATION FROM DUAL;

the output will display the interval of 100 months converted to years and the remaining months. 100 months is equal to 8 years and 4 months. Hence, the correct answer is:

DURATION +08-04

Regarding the properties and capabilities of virtual columns in Oracle Database:

C. They can be indexed: In Oracle, virtual columns can indeed be indexed. This allows for performance optimization on queries that utilize these columns, despite the fact that their values are derived and not stored physically.

D. They cannot have a data type explicitly specified: The data type of a virtual column is derived from the expression used to define it. Therefore, it is not specified explicitly but is inferred from the expression itself.

Incorrect options:

A: Virtual columns cannot be referenced in the WHERE clause of UPDATE or DELETE statements because they are not stored and cannot be individually modified.

B: Virtual columns cannot be referenced in the SET clause of an UPDATE statement since they are derived from other column values and cannot be updated directly.

E: Virtual columns cannot reference other virtual columns in their expressions due to the potential for recursive and complex dependencies.

Roles and privileges in Oracle manage access and capabilities within the database:

Option A : False. Roles are not " owned " in the traditional sense by the user who created them. They exist independently within the Oracle database and are assigned to users.

Option B : False. System privileges can be very granular, affecting specific types of operations or database objects, not always the entire database.

Option C : False. Roles are not owned by the SYS schema but are managed by database security and can be created by any user with sufficient privileges.

Option D : True. A role can indeed contain a combination of several privileges, including other roles, allowing for flexible and layered security configurations.

Option E : True. By default, a user has all object privileges for objects they own (i.e., objects in their schema).

Option F : False. PUBLIC is a special designation that applies to all users; individual privileges granted to PUBLIC cannot be revoked from a single user without revoking them from all users.

Option G : True. PUBLIC is a role granted by default to every user in an Oracle database, providing basic privileges necessary for general usability of the database.