Files
greptimedb/tests/cases/distributed
dennis zhuang 99ef93e143 fix(promql): follow IEEE 754 float semantics in comparisons and aggregations (#9479)
* fix(promql): follow IEEE 754 float semantics in operators and aggregations

- Comparisons: Arrow orders floats totally (NaN == NaN, NaN > +Inf); PromQL
  comparisons with NaN are false except !=.
- min/max: skip NaN unless the whole group is NaN. DataFusion's grouped
  min/max let NaN replace and be replaced by neighbours, so the result
  depended on input order.
- topk/bottomk rank NaN last.
- round() rounds ties up and returns NaN for a zero step, like Prometheus.
- sqrt() of a negative number is NaN instead of an error.

Signed-off-by: Dennis Zhuang <killme2008@gmail.com>

* fix(promql): round() without a step rounds to integers

The planner passed a zero step for single-argument round(), which now
yields NaN like Prometheus; pass 1 instead. Found by the compatibility harness.

Signed-off-by: Dennis Zhuang <killme2008@gmail.com>

* fix(promql): apply the sqrt guard to builtin functions and register min/max for plan decoding

sqrt resolves through the session's builtin functions, not the UDF branch.
Distributed plans are decoded with the serializer's session, which did not
know prom_min/prom_max.

Signed-off-by: Dennis Zhuang <killme2008@gmail.com>

* test(promql): cover NaN and rounding semantics

Signed-off-by: Dennis Zhuang <killme2008@gmail.com>

* fix(promql): keep the nested count rewrite for PromQL min/max

count(min(x) by (l)) was rewritten by count_nest_aggr only for the builtin
min/max names. prom_min/prom_max return NULL for the same groups, so the
rewrite stays valid. Update plan snapshots for the IEEE comparison, sqrt,
topk and min/max changes.

Signed-off-by: Dennis Zhuang <killme2008@gmail.com>

* fix(promql): register prom_min/prom_max in the function registry

Distributed plans split an aggregation into state and merge steps only for
functions whose state function exists in FUNCTION_REGISTRY; prom_min and
prom_max lived in the promql crate, so min/max stopped being pushed down to
datanodes. Move them to common-function and register them before the state
functions are derived.

Signed-off-by: Dennis Zhuang <killme2008@gmail.com>

* test: update sqlness results for PromQL float semantics

Plans and column names now show prom_min/prom_max, the NaN guards of
comparisons and sqrt, and the NaN sort key of topk. round() results follow
Prometheus' formula. Distributed min/max keep the state/merge split.

Signed-off-by: Dennis Zhuang <killme2008@gmail.com>

* fix(promql): keep column names and NULLs in IEEE comparisons and sqrt

Rewriting comparisons as `a op b AND NOT (isnan(a) OR isnan(b))` changed
TQL output column names and turned NULL operands into true for `!=` and
false for the bool forms. Implement comparisons and sqrt as PromQL UDFs
that propagate NULL and report the column name of the expression they
replace; prom_min/prom_max report min/max column names the same way.

Signed-off-by: Dennis Zhuang <killme2008@gmail.com>

* test: restore column names in sqlness results for PromQL float semantics

Signed-off-by: Dennis Zhuang <killme2008@gmail.com>

* test(promql): share the prom_min/prom_max groups accumulator with tests

Signed-off-by: Dennis Zhuang <killme2008@gmail.com>

* fix(promql): keep distinct names for prom_min/prom_max

Signed-off-by: Dennis Zhuang <killme2008@gmail.com>

---------

Signed-off-by: Dennis Zhuang <killme2008@gmail.com>
(cherry picked from commit f3a0841f4f)
Signed-off-by: WenyXu <wenymedia@gmail.com>
2026-10-12 12:49:21 +00:00
..
2023-05-30 08:55:24 +08:00