The ORDERS table has a constant transaction load 24 hours a day, so down time is not allowed. The index become fragmented. Whic statment is true ?
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The index need to be dropped, and then re-created.
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The resolution of index fragmentation depends on the type of index.
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The index can be rebuilt while users continue working on the table.
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The fragmented can be ignored because Oracle resolve index fragmentation by means of a freelist.
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The index can be rebuilt, but users will not have access to the index during this time.
Oracle allows online index rebuilds using the ALTER INDEX ... REBUILD ONLINE command. This operation rebuilds the fragmented index while maintaining DML operations on the underlying table. Dropping and recreating the index (option A) would work but causes more downtime. Option E is incorrect because users can continue working during an online rebuild. The fragmentation type (option B) doesn't determine whether you can rebuild online.
Oracle supports online index rebuilds via ALTER INDEX ... REBUILD ONLINE, which lets DML continue against the table (and even the index, with some restrictions) while the rebuild happens in the background. This avoids the downtime that a drop-and-recreate approach would require. Fragmentation resolution isn't type-dependent in the way one of the distractors claims, and Oracle does not silently fix fragmentation via freelists.