Last Attempt 1z0-071 Questions

• C. It executes successfully but ignores the ORDER BY clause because it is not located at the end of the compound statement: The ORDER BY clause in a compound query using UNION should be placed at the very end of the final SELECT statement. Since it's located with the first SELECT, it will be ignored.

Set operators allow you to combine multiple queries into a single query. The key points for each option are:

A. An expression in the first SELECT list does not need to have a column alias; however, the column alias given to an expression in the first SELECT list is used as the column name of the output.

B. This statement is true. When CHAR columns of different lengths are combined with a set operator, Oracle will pad the shorter values with spaces to match the length of the longest value. This behavior is consistent with the SQL standard and Oracle's treatment of the CHAR datatype.

C. Oracle Database performs implicit conversion between compatible data types where necessary when using set operators. For example, a NUMBER can be implicitly converted to a VARCHAR2 and vice versa if the context requires it.

D. This is true. When multiple set operators are used in a single query, the INTERSECT operator takes precedence over the UNION and UNION ALL operators. This order of operation can be overridden by using parentheses.

E. Not all set operators work with all data types. For instance, LOB and LONG RAW data types cannot be used with set operators.

References:

• Oracle Database SQL Language Reference, 12c Release 1 (12.1): "Set Operators"
• Oracle Database SQL Language Reference, 12c Release 1 (12.1): "Data Types"

A: True. A full outer join does indeed return both matched and unmatched rows from both tables involved in the join. It combines the results of both left and right outer joins.

E: True. An inner join, by definition, returns rows that have matching values in both tables. Rows from both tables that do not match are not returned in an inner join result set.

Inner joins match rows from the joined tables based on the join condition, while outer joins include all rows from one or both tables regardless of whether a matching row exists in the other table.

References:The Oracle SQL documentation explains different types of joins, including inner joins, left and right outer joins, and full outer joins, clarifying how they differ in the result sets they produce.

Multiple INSERT statements allow data insertion into one or more tables based on different conditions or datasets:

• Option A: False. Multiple INSERT operations can be performed using direct values, subqueries, or even default values, not exclusively through subqueries.
• Option B: True. They can indeed be performed on relational tables, which is the standard use case in most relational databases.
• Option C: True. INSERT operations can be performed on updatable views, assuming the view is not complex (involving joins, GROUP BY clauses, etc.).
• Option D: True. Oracle allows INSERT operations on remote tables via database links, enabling distributed database interactions.
• Option E: False. Direct INSERT statements cannot be performed on external tables. External tables are typically used for read operations, with data loading handled through utilities like SQL*Loader or external data processing tools.
• Option F: False. Each INSERT statement inserts data into one table. While a single SQL command block can contain multiple INSERT statements, each one is directed at a single table.