#9104 landed its own NULL-sample case whose data is the same series this
one already used: one host with interior NULLs, one host with nothing
but NULLs. Keeping both means two files asserting the same semantics on
the same rows.
The merged case keeps every query from both, so the presence functions
still cover the trailing-NULL window, the count of two, the empty
left-open window at t=7, and the all-NULL windows.
Signed-off-by: Dennis Zhuang <killme2008@gmail.com>
Review follow-up. Two things surfaced once range functions started
returning NULL for a window without samples.
The filter after a function call required every field column to be
non-NULL, so on a multi-field table one field with no samples in a
window would drop the other fields' results with it. It now keeps a row
when any field has a sample, which is the shape a selector already
emits. On a single field column the two predicates are identical.
`quantile_over_time` returned NaN rather than NULL for a window without
samples, so the row survived that filter. Prometheus returns an empty
vector there, so the emptiness check now sits in the range UDF; the
shared quantile kernel still yields NaN for an empty slice, matching
upstream's `quantile()` helper that `quantile_aggr` depends on.
Signed-off-by: Dennis Zhuang <killme2008@gmail.com>
Range functions read the value column through `Float64Array::values()`,
which returns the raw buffer and ignores the null bitmap. A NULL field
value means the series has no sample at that timestamp, so the padding
under a null slot (0.0 in practice) was counted as a real sample.
`rate`, `increase`, `delta`, `changes`, `resets`, `idelta`, `irate`,
`quantile_over_time` and `avg_over_time` now work on samples instead of
slots. `stddev_over_time` and `stdvar_over_time` used to panic on a NULL
slot, and tokio swallowed the panic so the query returned success with
that series missing.
Null handling is gated on `null_count() == 0` over the whole backing
array, checked once per batch, so tables without NULLs keep the existing
code path. `deriv` and `predict_linear` already had this guard through
`linear_regression_slices` and are untouched.
Signed-off-by: Dennis Zhuang <killme2008@gmail.com>
Dennis Zhuang