gluesql / gluesql / 31995576011

99%

Build Type

push

github

Committed by web-flow

Commit Message

Skip NULL values in non-COUNT aggregates (#1990)

SQL eliminates NULL before applying a set function, but SUM, MIN, MAX,
AVG, VARIANCE, and STDEV fed every evaluated value straight into the
accumulator. A single NULL therefore poisoned SUM/AVG/VARIANCE/STDEV
through Value::add, and a NULL in the first row of a group became a
sticky initial value for MIN/MAX because Value::Null.evaluate_cmp
returns None. COUNT was already correct.

Return early from State::accumulate for NULL inputs to every aggregate
but COUNT, so the invariant lives in one place and AggrValue never sees
NULL. Groups with no non-NULL input keep an empty slot and already
export empty_value, which is Null for these aggregates.

The aggregate fixtures encoded the old behavior as expected output, so
sum, avg, variance, stdev, and expr are updated to the standard results,
and a new null fixture covers leading NULLs, all-NULL columns, DISTINCT,
and per-group elimination.

Coverage Stats

3 of 3 new or added lines in 1 file covered. (100.0%)

1 existing line in 1 file now uncovered.

52890 of 53486 relevant lines covered (98.89%)

1562.41 hits per line