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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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