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      Question

      In a data analysis workflow, an index is created on a

      column with very low cardinality (e.g., a 'gender' column). What is a potential consequence of this?
      A Significantly improved query performance Correct Answer Incorrect Answer
      B Increased storage space for the index, but no performance gain Correct Answer Incorrect Answer
      C The index might not be used by the query optimizer Correct Answer Incorrect Answer
      D Faster write operations Correct Answer Incorrect Answer
      E Automatic data compression Correct Answer Incorrect Answer

      Solution

      For columns with very low cardinality (few distinct values), an index might not be beneficial. The query optimizer might decide that a full table scan is more efficient than using the index, as the index would point to a large percentage of the rows anyway.

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