Exam 1z0-071 topic 1 question 96 discussion

Actual exam question from Oracle's 1z0-071

Question #: 96
Topic #: 1

[All 1z0-071 Questions]

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

A. Setting an indexed column to unused results in an error.
B. You can query the data dictionary to see the names of unused columns.
C. You can specify multiple column names in an ALTER TABLE...SET UNUSED statement.
D. If you set all the columns of a table to unused, the table is automatically dropped.
E. CASCADE CONSTRAINTS must be specified when setting a column to unused if that column is referenced in a constraint on another column.

Show Suggested Answer

Suggested Answer: CE 🗳️

by Sbablo at May 26, 2023, 4:49 p.m.

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f4a3ee3

6 days, 9 hours ago

Selected Answer: BC

From Oracle documentation: You can view all tables with columns marked UNUSED in the data dictionary views USER_UNUSED_COL_TABS, DBA_UNUSED_COL_TABS, and ALL_UNUSED_COL_TABS. Source: https://docs.oracle.com/en/database/oracle/oracle-database/23/sqlrf/ALTER-TABLE.html

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ShahedOdeh

10 months ago

C and D

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ShahedOdeh

10 months ago

B and C

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lucemqy

1 year, 8 months ago

Selected Answer: CE

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

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ShahedOdeh

10 months ago

no we have the USER_TAB_COLUMNS dictionary that is showing the unused columns

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musafir

2 years ago

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

upvoted 2 times

shotcom

1 year, 9 months ago

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

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