Oracle Database Administration I: 1Z0-082

Which three statements are true about external tables in Oracle 18c and later releases? (Choose three.)

A. External table files can be used for other external tables in a different database

B. The ORACLE_LOADER access driver can be used to unload data from a database into an external table

C. The ORACLE_DATAPUMP access driver can be used to unload data from a database into an external table

D. They cannot be partitioned

E. The ORACLE_DATAPUMP access driver can be used to load data into a database from an external table

F. They support UPDATEs but not INSERTs and DELETEs

Which three statements are true about dropping and unused columns in an Oracle database? (Choose three.)

A. A primary key column referenced by another column as a foreign key can be dropped if using the CASCADE option.

B. An UNUSED column's space is reclaimed automatically when the block containing that column is next queried.

C. An UNUSED column's space is reclaimed automatically when the row containing that column is next queried.

D. Partition key columns cannot be dropped.

E. A DROP COLUMN command can be rolled back

F. A column that is set to UNUSED still counts towards the limit of 1000 columns per table

Which two are true about a SQL statement using SET operators such as UNION? (Choose two.)

A. The data type group of each column returned by the second query must match the data type of the corresponding column returned by the first query.

B. The number, but not names, of columns must be identical for all SELECT statements in the query.

C. The data type of each column returned by the second query must exactly match the data type of the corresponding column returned by the first query.

D. The names and number of columns must be identical for all SELECT statements in the query.

E. The data type of each column returned by the second query must be implicitly convertible to the data type of the corresponding column returned by the first query.