You are working on a decision support system (DSS). The index is available on the COUNTRY_ID column of the CUSTOMERS table.View the Exhibit and examine the parameter settings and the query execution plan.
Why is the query using a full table scan instead of an index scan?
Select an option, then click Submit answer.
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because the histogram statistics for the COUNTRY_ID column are not updated
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because the index statistics for the index on the COUNTRY_ID column are not current
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because the DB_FILE_MULTIBLOCK_READ_COUNT initialization parameter is set to a higher value
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because the optimizer predicts that most of the blocks in the table are accessed. Therefore, it uses a full table scan, even though indexes are available.
