[gitRasheed]

Summary

Fixes #10723

Reading one field of a nested column returned a different field, because readSchema() described pruned structs while the native scan returns each top-level column whole.

Changes

pruneColumns now keeps each required column with its full table type, in table order, so readSchema() matches what the reader returns. A query that uses one field of a nested column still reads the whole column.

VortexNestedSchemaPruningTest selects a non-first field from a struct, an array of structs, a map of structs and a struct inside a struct. All four fail without the fix. VortexScanBuilderTest.pruneColumnsKeepsTableTypes checks the read schema directly.

I used AI tools to help write and review this change.

[codspeed]

Merging this PR will degrade performance by 17.8%

3 warnings, 1 note

⚠️ Walltime results may be unreliable

Some benchmarks used the Walltime instrument outside CodSpeed Macro Runners, which can make the results inconsistent.

Learn more about Macro Runners

See affected benchmarks

⚠️ Unable to measure the execution of 2 benchmarks

These benchmarks measured no execution time, so their results are not comparable and count as unchanged. This usually happens when the compiler removes the code under test.

Prevent compiler optimizations

See affected benchmarks

⚠️ 17 benchmarks are dominated by system calls

System calls cannot be simulated consistently and are left out of the measure. The reported value understates the real cost. Switch to the Walltime instrument to measure them.

Learn more about system calls

See affected benchmarks

ℹ️ 40 benchmarks have no flamegraph

The flamegraph wasn't generated: the symbols of the profiling trace could not be resolved, because no information about the language frames was collected.

See affected benchmarks

⚡ 1 improved benchmark
❌ 7 regressed benchmarks
✅ 2400 untouched benchmarks
⏩ 12 skipped benchmarks¹

Warning

Please fix the performance issues or acknowledge them on CodSpeed.

Performance Changes

	Mode	Benchmark	BASE	HEAD	Efficiency
❌	Walltime	threshold_neon[8]	1.3 µs	2.4 µs	-45.42%
❌	Walltime	threshold_neon[64]	2.6 µs	3.6 µs	-28.8%
❌	Walltime	filter_neon[8]	880 ns	1,142 ns	-22.94%
❌	Walltime	threshold_neon[80]	3.9 µs	4.6 µs	-14.76%
❌	Walltime	filter_neon[64]	1.7 µs	1.9 µs	-10.18%
❌	Walltime	filter_neon[80]	2.5 µs	2.8 µs	-10.18%
❌	Walltime	words_gather_dispatch_neon[65536]	1.8 µs	2 µs	-10.02%
⚡	Walltime	bitpack_blocked_compress_avx2	7.5 µs	6.7 µs	+12.51%

Tip

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

---

_{Comparing gitRasheed:spark-nested-schema-pruning-fix (a7744f2) with develop (2f2dfce)²}

Footnotes

1. 12 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. ↩

2. No successful run was found on develop (756f1eb) during the generation of this report, so 2f2dfce was used instead as the comparison base. There might be some changes unrelated to this pull request in this report. ↩