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PostgreSQL compatibility: log(0.0::float8) should error, not return -inf #22261
Description
Split out from #22247.
Mismatch
log(0.0::float8) should error, not return -inf.
SELECT log(0.0::float8);PostgreSQL:
ERROR: cannot take logarithm of zero
DataFusion:
-inf
Expected behavior
For PostgreSQL-compatible SQL semantics, DataFusion should either match PostgreSQL's result or raise the same class of domain/semantic error.
Activity
xiedeyantu commentedon May 16, 2026
take
xiedeyantu commentedon May 17, 2026
If the changes in #22308 are approved, I can begin this task.
kuppalaadvaith-alt commentedon May 31, 2026
kuppalaadvaith-alt commentedon May 31, 2026
shinzoxD commentedon Aug 15, 2026
I'm working on this.
Context: I first looked at #22263 (
SIMILAR TO%wildcard), but that already has approved PR #23188, and the preferred fallbacks #22269 / #23258 are assigned. This sibling from the #22247 split is still open with no open PR.I'll keep the change tightly scoped to the issue:
log(0.0::float8)(and other zero values) become the PostgreSQL domain errorcannot take logarithm of zero. I will not changelog(1, 64)/ zero-base behavior, or the existinglogsimplifications, so this stays out of the scope-creep that closed #22564.@xiedeyantu I saw you previously took this and opened #22564. Please let me know if you are still working on a follow-up and I'll step back.
shinzoxD commentedon Aug 19, 2026
Leaving a note per the contributor guide: #22564 was closed, and there has been no follow-up PR since May. I opened #24399 for the scoped zero-value domain error (plus planner-simplification guards so
log(0, 0)cannot fold to 1). Happy to step aside if you still want to take this one, @xiedeyantu.Jefffrey commentedon Aug 29, 2026
logfunction to be in sync with PostgresSql #5259