discord9 9e2991f098 feat(query): bridge native histograms to columnar samples (#9602)
I hereby agree to the terms of the [GreptimeDB
CLA](https://github.com/GreptimeTeam/.github/blob/main/CLA.md).

## Refer to a related PR or issue link (optional)

Target: `narthex`, which now contains merged #9598 and #9599. Their
landed changes have been synchronized without rewriting feature history,
so this PR remains the histogram bridge increment.

## What's changed and what's your intention?

Connect the existing native-histogram representation to the shared
columnar sample containers. The incremental diff is limited to
`common-query/src/native_histogram.rs`.

- Re-export the shared `CounterResetHint` at its existing query-module
path, preserving numeric conversions and unknown values. Add an
owned-histogram adapter to `HistogramBatchBuilder`.
- Add a quantile entrypoint for borrowed `HistogramView` values. It
shares the existing quantile calculations and preserves early-return
precedence, custom/exponential bucket behavior and NaN information.
Borrowed-view validation does not tighten the legacy owned histogram's
malformed-layout behavior.
- Normalize persisted Arrow histogram structs directly into an owning
`Samples` value, without reconstructing a per-row owned
`NativeHistogram`. Preserve row positions, parent nulls, complete
payload bits, both bucket sides, reset/start metadata, and sliced-parent
offsets. Float payloads take precedence when present; stored integer
bucket counts are already absolute and are converted directly, with a
missing zero count defaulting to zero.
- Reject missing required scalar values, null list items and invalid
span layouts. The existing `read_histogram` decoder and persisted struct
schema remain unchanged.

Normalization borrows source values while reading and then copies them
into the canonical owning batch; integer conversion uses temporary
buffers. The borrowed quantile path still derives bucket/index buffers.
This is not an allocation-free or measured-performance claim. Scanner,
frame/Flight, execution-operator and public HTTP/TQL/SQL integration are
not included, and no persisted or network format changes.

### Validation

Ten new focused tests cover borrowed quantiles and NaN information,
malformed/overflow spans and early-return precedence, legacy
owned-layout compatibility, complete payload bit preservation, nonzero
batch/parent slices after original owners drop, empty/all-null input,
integer counts and float-family selection, and
required-field/list-item/span errors.

- Rust 1.98.1: `cargo check --locked -p datatypes -p common-query -p
promql --all-targets` — passed.
- Rust 1.98.1: `cargo nextest run --locked -p datatypes -p common-query
-p promql --retries 0 --no-fail-fast` — 707 passed, 0 skipped, both
before and after the final test-noise cleanup. The actual listing
includes all new tests and the parent buffer-capacity regression.
- The three cleanup-affected payload/lifecycle/empty tests were also run
explicitly — 3 passed; the complete unfiltered suite then passed all
707.
- Rust 1.99.0: `rustfmt --edition 2024 --config skip_children=true
--check src/common/query/src/native_histogram.rs` — passed.
- Scoped `hawkeye format` and `hawkeye check` on a byte-identical source
copy, plus `git diff --check` — passed. A missing-header negative
control confirmed that the scoped license check inspects the file.
- Rust 1.99.0: `cargo clippy --locked --no-deps -p common-query -p
promql --all-targets -- -D warnings` — blocked by
`async_trait`-generated `clippy::double_must_use` at unchanged
`common-query/src/logical_plan.rs:129`. The exact same command on the
exact parent commit `7e5acfb9a9c` reproduces that failure. Pinned 1.98.1
Clippy is unavailable in the local read-only toolchain. No lint or CI
policy was weakened; this is not a passing Clippy or full-workspace
validation claim.

### Diff-scoped cleanup

No whole tests were deleted. Removed only an empty-result assertion that
accepted every dense-storage representation after exact length was
already verified; the same named test retains empty/two-null conversion,
length and missing-position checks. Simplified payload assertions to
explicit histogram bindings and a shared complete bitwise assertion
helper, and renamed the payload test to describe its explicit
expected-value oracle. Public API rustdoc, ownership rationale and
compatibility/precedence contracts remain. No scanner, protocol or
unrelated cleanup is bundled.

### Verified review follow-up

- Current tested/pushed head:
`1164877b5a5982d0cea2860e01e1c28714299e9e`, including the merged #9599
parent. The only query-file conflict resolution relocates the same enum
re-export and retains the exact landed reset-hint identity regression;
no bridge/helper code was dropped. Independently reviewed after
resolution.
- Owned `all_buckets` and borrowed-view quantile execution now share one
private `assemble_bucket_sides`; no duplicate negative reversal or
zero-bucket rule remains. Fallible side builders, validation and
custom-bound handling are unchanged.
- A focused expected-sequence regression independently checks bounds,
counts and boundary rules, including insertion for nonzero count and
omission for both signed zeros.
- On the final synchronized head, Rust 1.98.1 all-target check and
complete `common-query / promql / datatypes` nextest: **712/712, 0
skipped** (76 + 301 + 335). Strict datatypes-only Rust 1.99 Clippy
passes. The earlier strict three-package run reports the existing
common-query macro diagnostic; the final known-category comparison
passes, not strict query lint. Normal formatting/TOML/license hooks
pass.

## PR Checklist
Please convert it to a draft if some of the following conditions are not
met.

- [x] I have written the necessary rustdoc comments.
- [x] I have added the necessary unit tests and integration tests.
- [ ] This PR requires documentation updates.
- [x] API changes are backward compatible.
- [x] Schema or data changes are backward compatible.
- [ ] This PR needs to be backported to release branches, and I have
added the `backport-<target>` labels (e.g. `backport-v1.3` targets
`release/v1.3`).
2026-10-15 18:20:43 +08:00
2023-08-10 08:08:37 +00:00
2023-06-25 11:05:46 +08:00
2023-11-09 10:38:12 +00:00

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