Oracle 1Z0-071 Exam Dumps

In the provided SQL query, the issue arises from the alias 'a.avg_sal' which is defined in the subquery but is being referenced in the SELECT list of the outer query. This is not permitted in SQL as the scope of the alias defined in the subquery is only within that subquery.

Here is the breakdown of the code and the error:

Line 1: Correct syntax for initiating a SELECT statement.

Line 2: Refers to 'e.salary', which is a correct reference to the 'salary' column using alias 'e' for the employees table.

Line 3: 'a.avg_sal' attempts to reference an alias that is defined in the subquery within the outer query, which is not allowed. This is because 'avg_sal' is defined in the subquery's SELECT list and cannot be referenced outside of it. The correct way to include the average salary from the subquery in the SELECT list of the main query would be to repeat the subquery or to use a join that includes the average salary.

Line 5-7: The subquery itself is correctly formed; it computes the average salary for the same department.

Line 8: The ORDER BY clause is properly referencing 'e.last_name', which is defined in the outer query.

Therefore, the error occurs at Line 3 where 'a.avg_sal' is not a valid reference in the SELECT list of the main query because it is defined in the subquery.

The rules of scope for aliases in subqueries are specified in the Oracle Database SQL Language Reference 12c documentation. Subquery aliases cannot be referenced outside their subquery.

For the SELECT statement from two tables without a JOIN clause:

Option B: You can add a WHERE clause with filtering criteria.

A WHERE clause can be added to a query to filter the results based on specified conditions.

Option E: It returns the same rows as SELECT * FROM bricks CROSS JOIN colors.

A comma-separated list of tables in a FROM clause is equivalent to a CROSS JOIN, resulting in a Cartesian product of the tables.

Options A, C, and D are incorrect because:

Option A: You cannot add an ON clause without changing the comma-separated FROM clause to a proper JOIN.

Option C: It returns the Cartesian product, not the sum, of the rows from BRICKS and COLORS.

Option D: A USING clause is not applicable without changing the syntax to a proper JOIN.

Synonyms in Oracle Database are aliases for database objects.

A . Correct. A synonym can be created for another synonym, essentially chaining synonyms. B. Incorrect. Private synonyms must be unique within a schema. However, because each user has their own schema, multiple users can have private synonyms with the same name, each pointing to objects in their respective schemas. C. Correct. Any user with the necessary privileges can create a PUBLIC synonym, which is accessible to all users. D. Incorrect. A synonym cannot be created for an object within a package, but it can be created for the package itself. E. Incorrect. Synonyms, like views, do not have object numbers because they do not occupy space in the database as tables do.

Reference can be found in the Oracle Database SQL Language Reference documentation, which details the rules and functionality of synonyms.

The statement that will fail is B. In Oracle SQL, the WHERE clause cannot contain aggregate functions directly. The HAVING clause is used instead to apply conditions that involve aggregates, but it is applied after the GROUP BY clause.

A . While the HAVING clause is used before the GROUP BY clause which is not standard SQL syntax, Oracle SQL may still execute it successfully due to its flexibility in syntax.

B . This statement will fail because it uses an aggregate function, COUNT(*), in the WHERE clause, which is not allowed. The correct approach is to use the HAVING clause to filter the results of aggregate functions after the GROUP BY clause.

C . This statement is correct; it places the HAVING clause after the GROUP BY clause, applying the filter on the aggregated count.

D . This is a correctly constructed statement with the WHERE clause filtering individual records before grouping, and the HAVING clause filtering groups based on the aggregate function.

Oracle Database SQL Language Reference, 12c Release 1 (12.1): 'WHERE Clause'

Oracle Database SQL Language Reference, 12c Release 1 (12.1): 'HAVING Clause'

Regarding the DROP TABLE command:

A . ALL constraints defined on HR.EMPLOYEES are dropped: Dropping a table will automatically drop all constraints associated with that table.

B . The HR.EMPLOYEES table may be moved to the recycle bin: In Oracle, unless explicitly using PURGE, dropped tables go to the recycle bin, allowing recovery.

E . All indexes defined on HR, EMPLOYEES are dropped: When a table is dropped, all its indexes are also automatically dropped.

Incorrect options:

C: Synonyms are not automatically dropped when the table is dropped; they become invalid.

D: Sequences are independent objects and are not dropped when a table is dropped.

F: Views are not dropped; however, they will return errors upon being queried if their base table is dropped.