Oracle Updated 1z0-071 Exam Questions and Answers by alisa

For Transaction Control Language (TCL) operations:

• A. COMMIT erases all the transaction’s savepoints and releases its locks: When a COMMIT operation is executed, it finalizes all changes made during the transaction, removes any savepoints that have been set during the transaction, and releases any locks held on the database objects by the transaction.
• B. COMMIT ends the transaction and makes all its changes permanent: A COMMIT command completes the transaction, making all data modifications permanent and visible to other sessions.
• E. ROLLBACK without the TO SAVEPOINT clause undoes all the transaction's changes, releases its locks, and erases all its savepoints: The ROLLBACK command, when used without specifying a SAVEPOINT, undoes all changes made during the transaction, releases any locks held, and removes any savepoints that were established during the transaction.

Incorrect options:

• C: ROLLBACK, without any specification, not only undoes all the transaction's changes but also releases all locks held by the transaction.
• D: ROLLBACK to a SAVEPOINT only undoes changes up to the named savepoint and does not end the transaction; the transaction continues until a COMMIT or a full ROLLBACK is issued.
• F: ROLLBACK without a TO SAVEPOINT clause also erases all savepoints created during the transaction.

B. True. This statement will execute successfully because it has a single column in the SELECT statements combined with UNION, and the ORDER BY clause is referencing a valid column in the result set.

A is incorrect because it uses an ORDER BY clause with two columns, which is not allowed when the SELECT statements have only one column each. C is incorrect for the same reason as A; it references columns that do not exist in the result set. D is incorrect because it attempts to ORDER BY a second column, which does not exist in the result of the union.

In SQL, the WHERE and HAVING clauses are used to filter records; the WHERE clause is applied before grouping the records, while the HAVING clause is used after grouping the records, particularly when using aggregation functions.

• Statement D is true because the HAVING clause is used to filter groups based on the result of aggregate functions. Therefore, any column or aggregate function appearing in the HAVING clause must also appear in the SELECT list of the query, unless it is used as part of an aggregate function.
• Statement E is true because the WHERE clause is designed to filter rows before they are grouped into aggregate groups in a GROUP BY clause. This is a fundamental aspect of SQL that optimizes query performance by reducing the number of rows to be processed in the aggregate phase.
• Statements A, B, and C are incorrect based on the following:

D: True. A BLOB (Binary Large Object) is used to store unstructured binary data within the Oracle Database. It can hold a variable amount of data.

F: True. A BFILE is a datatype in Oracle SQL used to store a locator (pointer) that points to binary data stored in operating system files outside of the Oracle Database.

Both BLOB and BFILE are used for large binary data but differ in where the data is actually stored - BLOB stores the data inside the Oracle Database, whereas BFILE stores the data in the file system outside the database.

References:The Oracle Database SQL Language Reference guide details the characteristics and uses of BLOB and BFILE datatypes among others, describing their storage characteristics and data type definitions.