Oracle 1z0-071 Exam With Confidence Using Practice Dumps

For question 134, the correct options are B and F based on the capabilities and design of SQL:

B. It best supports relational databases: SQL is fundamentally designed to manage and query data in relational databases. It is the standard language used for managing relational database management systems (RDBMS) and for performing all types of data operations within them.

F. It provides independence for logical data structures being manipulated from the underlying physical data storage: SQL allows users to interact with the data at a logical level without needing to know how the data is physically stored. This is known as logical data independence, which is a key feature of SQL in managing databases.

Other options are incorrect because:

A: SQL itself doesn't guarantee ACID properties; these are provided by the database management system's transaction control mechanisms.

C, D, E: These statements are incorrect as SQL does not inherently support object-oriented concepts like encapsulation and polymorphism, is not limited to hierarchical data storage, and is not the only language used for both relational and object-oriented databases.

Single-row functions in SQL operate on each row independently and can modify the returned value:

Option A: Incorrect. Single row functions can be used in multiple parts of a SELECT statement, including SELECT, WHERE, and ORDER BY clauses.

Option B: Incorrect. Single row functions can accept more than one argument, such as the CONCAT function, which can accept multiple string arguments.

Option C: Incorrect. They return one result for each row processed, not per table.

Option D: Correct. Single row functions can take various types of arguments including column names, literals, variables, and other expressions.

Option E: Correct. Functions can be nested within other functions, allowing complex expressions and calculations.

Option F: Correct. The data type of the result can differ from the arguments’ data types, such as the SUBSTR function returning a VARCHAR2 even when used on a number after converting it to a string.

The ORDER BY clause is used in a SELECT statement to sort the returned rows by one or more columns.

A. This clause would attempt to order by ename as if it were a numeric column, which is not correct since ename is not numeric.

B. This is the correct answer. The NVL function replaces nulls with the specified value, in this case, 0. This clause sorts by comm, with nulls considered as 0 and appearing first, followed by the actual values, and then sorts by ename.

C. This clause is incorrect because it would place null values at the end, but in the output, rows with null comm appear at the beginning.

D. This clause would sort the comm in descending order with the nulls at the end, which is not consistent with the output shown.

References:

Oracle Database SQL Language Reference, 12c Release 1 (12.1): "ORDER BY Clause"

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

Please note that the correct formatting of SQL statements and clauses is crucial for the successful execution of queries.