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Question 96

Which two are true about unused columns? (Choose two.)

Setting an indexed column to unused results in an error.

You can query the data dictionary to see the names of unused columns.

You can specify multiple column names in an ALTER TABLE...SET UNUSED statement.

If you set all the columns of a table to unused, the table is automatically dropped.

CASCADE CONSTRAINTS must be specified when setting a column to unused if that column is referenced in a constraint on another column.

Correct Answer: C, E

You can specify multiple column names in an ALTER TABLE...SET UNUSED statement. Additionally, CASCADE CONSTRAINTS must be specified when setting a column to unused if that column is referenced in a constraint on another column.

Discussion

musafirOptions: BC

B C E are all correct according to Oracle "SET UNUSED Clause" https://docs.oracle.com/en/database/oracle/oracle-database/23/sqlrf/ALTER-TABLE.html#GUID-552E7373-BF93-477D-9DA3-B2C9386F2877

shotcom

when you query the dba_unused_col_tabs view which displays a list of all tables with un-used columns, including counts of the number of columns within a table that are unused but it will not show the names of the unused columns so B is wrong

lucemqyOptions: CE

CE is correct you can see number of unused columns but not their names in the data dictionary

NelitaOptions: CE

CE ARE CORRECT.

SbabloOption: E

All are wrong except E

shotcom

C is correct, you can specify multiple columns in a single alter statement eg: ALTER TABLE EMPLOYEES SET UNUSED (JOB_ID, COMMISSION_PCT);

SbabloOptions: BE

Correct answer B,E