Which two statements regarding unusable indexes are correct? (Choose two.)
A.
You can set SKIP_UNUSABLE_INDEXES to true to skip unusable indexes.
B.
You do not need to set any parameter because unusable indexes are skipped
automatically.
C.
Your Data Definition Language (DDL) statement shows a warning message when an
index is made unusable.
D.
You can check the alert log file to get a message recorded about unusable indexes.
Explanation: