Regression in json performance for local files

[ariel-miculas]

I ran some tests with clickbench, reading from local files is worse after we merged #20823

[ec2-user@ip-172-31-0-185 datafusion]$ ./benchmarks/bench.sh compare json-test-on-main test-json-improvement
Comparing json-test-on-main and test-json-improvement
--------------------
Benchmark clickbench_2.json
--------------------
┏━━━━━━━━━━━┳━━━━━━━━━━━━━━━━━━━┳━━━━━━━━━━━━━━━━━━━━━━━┳━━━━━━━━━━━━━━━┓
┃ Query     ┃ json-test-on-main ┃ test-json-improvement ┃        Change ┃
┡━━━━━━━━━━━╇━━━━━━━━━━━━━━━━━━━╇━━━━━━━━━━━━━━━━━━━━━━━╇━━━━━━━━━━━━━━━┩
│ QQuery 0  │        2938.54 ms │           36468.92 ms │ 12.41x slower │
│ QQuery 1  │        4189.48 ms │           36706.26 ms │  8.76x slower │
│ QQuery 2  │        3021.24 ms │           36695.04 ms │ 12.15x slower │
│ QQuery 3  │              FAIL │                  FAIL │  incomparable │
│ QQuery 4  │        3518.24 ms │           37016.08 ms │ 10.52x slower │
│ QQuery 5  │        3138.41 ms │           37131.63 ms │ 11.83x slower │
│ QQuery 6  │              FAIL │                  FAIL │  incomparable │
│ QQuery 7  │        4191.68 ms │           36874.60 ms │  8.80x slower │
│ QQuery 8  │        4405.33 ms │           37054.97 ms │  8.41x slower │
│ QQuery 9  │        3473.41 ms │           37308.28 ms │ 10.74x slower │
│ QQuery 10 │        4351.06 ms │           36934.39 ms │  8.49x slower │
│ QQuery 11 │        3306.45 ms │           37101.39 ms │ 11.22x slower │
│ QQuery 12 │        3226.21 ms │           37235.60 ms │ 11.54x slower │
│ QQuery 13 │        3970.11 ms │           37244.27 ms │  9.38x slower │
│ QQuery 14 │        3246.59 ms │           37085.69 ms │ 11.42x slower │
│ QQuery 15 │        4563.53 ms │           37182.89 ms │  8.15x slower │
│ QQuery 16 │        4506.85 ms │           37391.07 ms │  8.30x slower │
│ QQuery 17 │        4377.16 ms │           37381.49 ms │  8.54x slower │
│ QQuery 18 │        3555.18 ms │           37603.25 ms │ 10.58x slower │
│ QQuery 19 │        4568.01 ms │           36996.50 ms │  8.10x slower │
│ QQuery 20 │        3193.87 ms │           37069.19 ms │ 11.61x slower │
│ QQuery 21 │        4415.33 ms │           37185.73 ms │  8.42x slower │
│ QQuery 22 │        3312.73 ms │           37190.81 ms │ 11.23x slower │
│ QQuery 23 │              FAIL │                  FAIL │  incomparable │
│ QQuery 24 │        4382.53 ms │           37093.81 ms │  8.46x slower │
│ QQuery 25 │        4339.69 ms │           37121.90 ms │  8.55x slower │
│ QQuery 26 │        4425.42 ms │           37106.02 ms │  8.38x slower │
│ QQuery 27 │        4505.30 ms │           37059.04 ms │  8.23x slower │
│ QQuery 28 │        3582.82 ms │           37409.12 ms │ 10.44x slower │
│ QQuery 29 │        4440.96 ms │           36868.93 ms │  8.30x slower │
│ QQuery 30 │        4675.71 ms │           37081.23 ms │  7.93x slower │
│ QQuery 31 │        4276.55 ms │           37165.64 ms │  8.69x slower │
│ QQuery 32 │        3615.42 ms │           37662.39 ms │ 10.42x slower │
│ QQuery 33 │        4446.09 ms │           37558.30 ms │  8.45x slower │
│ QQuery 34 │        4521.66 ms │           37647.72 ms │  8.33x slower │
│ QQuery 35 │        4321.41 ms │           37225.06 ms │  8.61x slower │
│ QQuery 36 │              FAIL │                  FAIL │  incomparable │
│ QQuery 37 │              FAIL │                  FAIL │  incomparable │
│ QQuery 38 │              FAIL │                  FAIL │  incomparable │
│ QQuery 39 │              FAIL │                  FAIL │  incomparable │
│ QQuery 40 │              FAIL │                  FAIL │  incomparable │
│ QQuery 41 │              FAIL │                  FAIL │  incomparable │
│ QQuery 42 │              FAIL │                  FAIL │  incomparable │
└───────────┴───────────────────┴───────────────────────┴───────────────┘
┏━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━┳━━━━━━━━━━━━━━┓
┃ Benchmark Summary                    ┃              ┃
┡━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━╇━━━━━━━━━━━━━━┩
│ Total Time (json-test-on-main)       │  131002.95ms │
│ Total Time (test-json-improvement)   │ 1225857.24ms │
│ Average Time (json-test-on-main)     │    3969.79ms │
│ Average Time (test-json-improvement) │   37147.19ms │
│ Queries Faster                       │            0 │
│ Queries Slower                       │           33 │
│ Queries with No Change               │            0 │
│ Queries with Failure                 │           10 │
└──────────────────────────────────────┴──────────────┘

The issue is the into_stream function of objects store's get_result reads data in 8KiB chunks for local files, so we need to either replace it with custom code or use a completely separate path for local files, as it was done previously

Originally posted by @ariel-miculas in #20823 (comment)

[ariel-miculas]

It would be nice to have this first: #21446

[alamb]

Thanks @ariel-miculas -- I think tince this is a regression we should make sure it is done before we release 54.0.0 -- I added it to the list on

• Release DataFusion 54.0.0 (Apr 2026 / May 2026) #21080

[Dandandan]

This was after #20823 ?

[ariel-miculas]

yes