Multiple choice technology databases

Index will not be used if ... Choose all that apply.

  1. NOT operator is used in the predicate

  2. IN Operator is used in the predicate

  3. Expression and/or functions are used on the indexed columns

  4. Predicate is skipped. However, the SELECT clause has indexed columns

  5. ORDER BY clause has NULL columns. However, NON UNIQUE index exists
Reveal answer Fill a bubble to check yourself
A,C,E Correct answer
Explanation

Indexes are bypassed when: NOT operator negates index usability (A), functions/expressions on indexed columns prevent direct index lookup (C), and ORDER BY with NULL columns on non-unique indexes may not use indexing effectively (E). IN operator (B) can use indexes, and SELECT clause columns (D) don't affect predicate indexing.

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