Exactprep 1z0-071 Questions

A: True. The DESCRIBE command can indeed be used from SQL Developer as well as other Oracle database tools such as SQL*Plus. This command is used to display the structure of a table, view, or other object, showing information such as column names, data types, and whether a column is nullable.

B: True. The DESCRIBE command can be used to display the structure of an existing view, showing similar information as it would for a table. This includes the columns, their data types, and other pertinent details.

D: True. When DESCRIBE is used, it does display the NOT NULL constraints for columns that have this constraint. This is part of the basic information about the structure of a table or view that can help developers understand the requirements of the data stored therein.

In the case of SQL commands TRUNCATE and DELETE:

A. the result of a delete can be undone by issuing a rollback: DELETE is a DML operation that affects rows individually and can be rolled back if it is performed within a transaction.

B. delete can use a where clause to determine which row(s) should be removed: DELETE operation allows the use of a WHERE clause to specify which rows should be deleted based on certain conditions.

Incorrect options are:

C: TRUNCATE does not support the use of a WHERE clause. It is designed to remove all rows from a table swiftly and cannot be conditional.

D: TRUNCATE does not leave indexes in an unusable state; it simply removes all rows.

E: TRUNCATE is a DDL command and its operation typically cannot be rolled back in many SQL database systems, including Oracle.

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.

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