Which two statement are correct?

On your Oracle 12c database, you Issue the following commands to create indexes
SQL > CREATE INDEX oe.ord_customer_ix1 ON oe.orders (customers_id, sales_rep_id) INVISIBLE;
SQL> CREATE BITMAP INDEX oe.ord_customer_ix2 ON oe.orders (customers_id, sales_rep_id);
Which two statement are correct?

On your Oracle 12c database, you Issue the following commands to create indexes
SQL > CREATE INDEX oe.ord_customer_ix1 ON oe.orders (customers_id, sales_rep_id) INVISIBLE;
SQL> CREATE BITMAP INDEX oe.ord_customer_ix2 ON oe.orders (customers_id, sales_rep_id);
Which two statement are correct?

A.
Both the indexes are created; however, only the ORD_COSTOMER index is visible.

B.
The optimizer evaluates index access from both the Indexes before deciding on which index to use for
query execution plan.

C.
Only the ORD_CUSTOMER_IX1 index is created.

D.
Only the ORD_CUSTOMER_IX2 index is created.

E.
Both the indexes are updated when a new row is inserted, updated, or deleted In the orders table.

Explanation:
11G has a new feature called Invisible Indexes. An invisible index is invisible to the optimizer as default. Using
this feature we can test a new index without effecting the execution plans of the existing sql statements or we
can test the effect of dropping an index without dropping it.



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clemente

clemente

Wrong answer!
the question would be

SQL > CREATE INDEX oe.ord_customer_ix1 ON oe.orders (customers_id, sales_rep_id)
SQL> CREATE BITMAP INDEX oe.ord_customer_ix2 ON oe.orders (customers_id, sales_rep_id)INVISIBLE;

In order to make Answer A correct

Jonesy

Jonesy

The question A should be
Both the indexes are created; however, only the ORD_COSTOMER_IX2 index is visible

So answers are AE