Execute spatial distance with RowFn

[connortsui20]

Rationale for this change

Moves spatial distance to the shared row executor. Each geometry column decodes once per batch, and a constant operand remains one decoded geometry.

• Progress towards: Epic: Row-oriented scalar functions #9128

What changes are included in this PR?

Adds the crate-private GeometryRow input element and expresses distance as a two-row kernel. Tests cover both constant positions, nullable inputs, mixed geometry types, and exact distance behavior.

Rust 1.97.1 one-CGU fat-LTO measurements keep the ordinary distance cases within 2.7% of develop; the nullable column-by-constant case improves by 13.9%.

What APIs are changed? Are there any user-facing changes?

There are no public API or behavior changes. SpatialDistance implements RowFn and receives the standard scalar-function vtable automatically.

[codspeed-hq]

Merging this PR will regress 1 benchmark

⚠️ Unknown Walltime execution environment detected

Using the Walltime instrument on standard Hosted Runners will lead to inconsistent data.

For the most accurate results, we recommend using CodSpeed Macro Runners: bare-metal machines fine-tuned for performance measurement consistency.

⚡ 1 improved benchmark
❌ 1 regressed benchmark
✅ 2049 untouched benchmarks
⏩ 89 skipped benchmarks¹

Warning

Please fix the performance issues or acknowledge them on CodSpeed.

Performance Changes

	Mode	Benchmark	BASE	HEAD	Efficiency
❌	WallTime	words_gather_scalar[65536]	8.3 µs	9.4 µs	-11.93%
⚡	Simulation	nullable_point_column_x_constant_point	758.3 µs	666 µs	+13.85%

Tip

Investigate this regression by commenting @codspeedbot fix this regression on this PR, or directly use the CodSpeed MCP with your agent.

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_{Comparing ct/row-fn-spatial-distance (8f44a47) with ct/row-fn-tensor-products (5f4a145)}

Footnotes

1. 89 benchmarks were skipped, so the baseline results were used instead. If they were deleted from the codebase, click here and archive them to remove them from the performance reports. ↩

[connortsui20]

Here are the local spatial-distance benchmark results from the final Rust 1.97.1 run.

The comparison used a develop baseline with benchmark-only backfills (1edd0fca) and the full RowFn stack (8ca9fc73). Later stack layers do not change spatial distance source, but unrelated code-placement effects can still affect these binaries.

The machine was an AMD Ryzen 9 7950X running Linux. The build used rustc 1.97.1, LLVM 22.1.6, one CGU, fat LTO, and -C target-cpu=native. Each target used two warm runs and seven alternating measured pairs. Each process used 100 samples with a 0.25–0.5 second measurement window on CPU 4.

Negative changes are faster. The values are medians across the seven paired runs.

The three ordinary distance cases remain within 2.65%. The nullable column-by-constant case improves by 13.85%.

All spatial-distance results: 4 cases

Benchmark	Baseline	RowFn stack	Change
point_column_x_constant_point	13.670 µs	14.080 µs	+2.65%
polygon_column_x_constant_polygon	33.550 µs	34.180 µs	+1.70%
point_column_x_point_column	17.140 µs	17.060 µs	+0.47%
nullable_point_column_x_constant_point	18.190 µs	15.680 µs	-13.85%