Why Don't More SQL Databases Have a Built-in PRODUCT Aggregate Function?

Why SQL Lacks a PRODUCT Aggregate Function

Many SQL databases lack a PRODUCT aggregate function, prompting users to seek alternatives. Unlike SUM, which accumulates numeric values additively, PRODUCT multiplies them. The absence of this aggregate raises questions.

One plausible explanation for the missing PRODUCT function lies in its computational complexity. Unlike SUM, calculating the product of multiple values requires multiple multiplications, making it computationally more expensive. Furthermore, extreme values can lead to overflow errors, especially with floating-point data.

Moreover, the PRODUCT function could lead to ambiguous results. For example, if a single row contains a zero value, the entire product would be zero, potentially masking non-zero values in other rows.

Despite the lack of a native PRODUCT aggregate, users can employ workarounds. For instance, in MSSQL, a combination of logarithms and aggregate functions can achieve a similar result. However, this method may introduce rounding errors if the values contain fractional components.

Other databases offer alternative approaches. PostgreSQL provides the PRODUCT() aggregate function, while MySQL and SQLite allow users to multiply values within a GROUP BY statement using the * operator.

While the lack of a native PRODUCT aggregate function may disappoint some users, its absence is likely due to computational concerns and the potential for ambiguous results. By understanding the limitations and exploring available workarounds, users can still achieve multiplication-based aggregation in their SQL queries.

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