morrySnow opened a new pull request, #67895:
URL: https://github.com/apache/doris/pull/67895
### What problem does this PR solve?
Issue Number: None
Related PR: None
Problem Summary:
Problem: Comparisons whose left side divides a value by a constant could
return incorrect booleans or lose NULL results after expression simplification.
Root cause: The arithmetic comparison rule treated division as algebraically
invertible and rewrote `x / c op r` as `x op r * c`. That equivalence does not
hold under SQL numeric coercion, floating-point and decimal rounding, overflow,
or division-by-zero semantics.
Reproduction: Division by zero should yield NULL, but the rewrite changed `x
/ 0 > 1` into `x > 0`. Finite non-zero counterexamples also differ at rounding
boundaries, including DOUBLE `0.30000000000000004 / 3.0 > 0.1`,
integer-to-DOUBLE `-100 / 11 > -9.090909090909092`, and DECIMAL `1 / 3 >
0.333333`.
Fix: Remove division from the inverse-rearrangement allowlist so the
complete Divide expression remains on its original side of the comparison. Keep
the existing additive and supported date/time rearrangements unchanged.
Tests: Add expression-rule unit coverage for zero representations, folded
zero, NULL, non-finite values, finite rounding boundaries, negative divisors,
and nested arithmetic. Add end-to-end plan and result regression coverage with
the rule enabled and disabled.
### Release note
Fix incorrect comparison results and lost NULL values for division
expressions with constant divisors.
### Check List (For Author)
- Test:
- Unit Test
- Regression test
- Full FE build and checkstyle
- Behavior changed: Yes. Division comparisons are kept intact unless a
future rewrite can prove SQL-semantic equivalence.
- Does this need documentation: No
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