Multiple choice technology databases

For which relational operators in where clause, index is not used ?

  1. <>

  2. like '%...' is NOT functions

  3. field +constant

  4. field||''

  5. AND
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A,B,C,D Correct answer
Explanation

Oracle indexes are typically bypassed for inequality operators (<>, !=), NOT functions, and expressions that wrap columns in functions or operations. The LIKE operator with a leading wildcard ('%...') prevents index usage, and expressions like field+constant or field||'' (concatenation) similarly disable indexes. The AND operator, when used with sargable (searchable) conditions, can effectively use indexes.

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