Multiple choice technology databases

For which of the following queries may a merge join be considered?

  1. Outer joins

  2. Multi-table updates and deletes

  3. Equi-joins

  4. Equi-join with a text column in select list
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Merge joins require sorted input datasets on the join keys, which means they are exclusively considered for equi-joins containing equality predicates. They cannot be used for non-equi joins, and text columns cannot be sorted, ruling out the other options.

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