Yuvraj-cyborg opened a new pull request, #19369: URL: https://github.com/apache/datafusion/pull/19369
## Which issue does this PR close? Closes #19348 ## Rationale for this change Previously, pow() on decimal types would error for negative exponents and non-integer exponents with messages like: - Arrow error: Arithmetic overflow: Unsupported exp value: -5 - Compute error: Cannot use non-integer exp - This was a regression from when decimals were cast to float before pow(). The efficient integer-based algorithm for computing power on scaled integers cannot handle these cases. ## What changes are included in this PR? - Modified pow_decimal_int to fallback to pow_decimal_float for negative exponents - Modified pow_decimal_float to use an efficient integer path for non-negative integer exponents, otherwise fallback to f64 computation Added pow_decimal_float_fallback function that: - Converts the decimal to f64 - Computes powf(exp) - Converts back to the original decimal type with proper scaling - Added decimal_from_i128 helper to convert i128 results back to generic decimal types (needed for Decimal256 support) - Updated sqllogictests to expect success for negative/non-integer exponents ## Are these changes tested? Yes: Unit tests for pow_decimal_float_fallback covering negative exponents, fractional exponents, cube roots Updated SQL logic tests in decimal.slt ## Are there any user-facing changes? Yes. The following queries now work instead of returning errors: ```sql -- Negative exponent SELECT power(4::decimal(38, 5), -1); -- Returns 0.25 -- Non-integer exponent SELECT power(2.5, 4.2); -- Returns 46.9 -- Square root via power SELECT power(4::decimal, 0.5); -- Returns 2 -- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. To unsubscribe, e-mail: [email protected] For queries about this service, please contact Infrastructure at: [email protected] --------------------------------------------------------------------- To unsubscribe, e-mail: [email protected] For additional commands, e-mail: [email protected]
