Which two are true about unused columns? (Choose two.)
Posted: Sun Jun 11, 2023 3:54 pm
Which two are true about unused columns? (Choose two.)
A. A query can return data from unused columns, but no DML is possible on those columns.
B. Unused columns retain their data until they are dropped.
C. Once a column has been set to unused, a new column with the same name can be added to the table.
D. The DESCRIBE command displays unused columns. E. A primary key column cannot be set to unused. F. A foreign key column cannot be set to unused.
A. A query can return data from unused columns, but no DML is possible on those columns.
B. Unused columns retain their data until they are dropped.
C. Once a column has been set to unused, a new column with the same name can be added to the table.
D. The DESCRIBE command displays unused columns. E. A primary key column cannot be set to unused. F. A foreign key column cannot be set to unused.