NULL Handling

One of the key aspects of aggregate functions in Oracle is their handling of NULL values. All aggregate functions, except for COUNT(*), ignore NULL entries. This behavior is important as it ensures that calculations are based solely on valid data. For example, when using SUM(), any NULL values in the column are excluded from the total. This prevents skewed results, especially in datasets where some entries may not have values. Understanding how aggregate functions treat NULLs is critical for accurate data analysis. It enables users to create queries that return meaningful results without being misled by missing data. For instance, in a sales report, counting only non-NULL sales figures provides a clearer picture of actual performance.