---
dataset_info:
- config_name: go-v1-hard-negatives-100k
  features:
  - name: query
    dtype: string
  - name: pos
    dtype: string
  - name: negs
    list: string
  splits:
  - name: train
    num_examples: 87536
- config_name: go-v1-pair-2M
  features:
  - name: query
    dtype: string
  - name: pos
    dtype: string
  splits:
  - name: train
    num_examples: 1532319
- config_name: java-v1-hard-negatives-100k
  features:
  - name: query
    dtype: string
  - name: pos
    dtype: string
  - name: negs
    list: string
  splits:
  - name: train
    num_examples: 80906
- config_name: java-v1-pair-2M
  features:
  - name: query
    dtype: string
  - name: pos
    dtype: string
  splits:
  - name: train
    num_examples: 1456651
- config_name: javascript-v1-hard-negatives-100k
  features:
  - name: query
    dtype: string
  - name: pos
    dtype: string
  - name: negs
    list: string
  splits:
  - name: train
    num_examples: 79484
- config_name: javascript-v1-pair-2M
  features:
  - name: query
    dtype: string
  - name: pos
    dtype: string
  splits:
  - name: train
    num_examples: 1298745
- config_name: php-v1-hard-negatives-100k
  features:
  - name: query
    dtype: string
  - name: pos
    dtype: string
  - name: negs
    list: string
  splits:
  - name: train
    num_examples: 74945
- config_name: php-v1-pair-2M
  features:
  - name: query
    dtype: string
  - name: pos
    dtype: string
  splits:
  - name: train
    num_examples: 1311302
- config_name: python-v1-hard-negatives-100k
  features:
  - name: query
    dtype: string
  - name: pos
    dtype: string
  - name: negs
    list: string
  splits:
  - name: train
    num_examples: 96670
- config_name: python-v1-pair-2M
  features:
  - name: query
    dtype: string
  - name: pos
    dtype: string
  splits:
  - name: train
    num_examples: 1779891
- config_name: ruby-v1-hard-negatives-100k
  features:
  - name: query
    dtype: string
  - name: pos
    dtype: string
  - name: negs
    list: string
  splits:
  - name: train
    num_examples: 67937
- config_name: ruby-v1-pair-2M
  features:
  - name: query
    dtype: string
  - name: pos
    dtype: string
  splits:
  - name: train
    num_examples: 1145414
configs:
- config_name: go-v1-hard-negatives-100k
  data_files:
  - split: train
    path: go-v1-hard-negatives-100k/train-*
- config_name: go-v1-pair-2M
  data_files:
  - split: train
    path: go-v1-pair-2M/train-*
- config_name: java-v1-hard-negatives-100k
  data_files:
  - split: train
    path: java-v1-hard-negatives-100k/train-*
- config_name: java-v1-pair-2M
  data_files:
  - split: train
    path: java-v1-pair-2M/train-*
- config_name: javascript-v1-hard-negatives-100k
  data_files:
  - split: train
    path: javascript-v1-hard-negatives-100k/train-*
- config_name: javascript-v1-pair-2M
  data_files:
  - split: train
    path: javascript-v1-pair-2M/train-*
- config_name: php-v1-hard-negatives-100k
  data_files:
  - split: train
    path: php-v1-hard-negatives-100k/train-*
- config_name: php-v1-pair-2M
  data_files:
  - split: train
    path: php-v1-pair-2M/train-*
- config_name: python-v1-hard-negatives-100k
  data_files:
  - split: train
    path: python-v1-hard-negatives-100k/train-*
- config_name: python-v1-pair-2M
  data_files:
  - split: train
    path: python-v1-pair-2M/train-*
- config_name: ruby-v1-hard-negatives-100k
  data_files:
  - split: train
    path: ruby-v1-hard-negatives-100k/train-*
- config_name: ruby-v1-pair-2M
  data_files:
  - split: train
    path: ruby-v1-pair-2M/train-*
license: apache-2.0
---
# cornstack-samples

🚧 This dataset is under active development and may change.

Filtered CoRNStack sample subsets for code retrieval training.

Source dataset and paper:
- CoRNStack collection: https://huggingface.co/collections/nomic-ai/cornstack
- CoRNStack paper: https://huggingface.co/papers/2412.01007

Note: the original CoRNStack collection is a much larger dataset family for code search training.
If you need large-scale data (not samples), please refer to the original CoRNStack collection above.

## What This Release Contains

This release keeps the original subset layout (6 languages x pair + hard-negatives) and applies deterministic rule-based filtering.

In this revision, query-level deduplication and positive-document (`pos`) deduplication are applied per subset.
For both rules, if duplicates exist, only the first row is kept.

## Config Layout And Schema

Each language is published as two configs with split `train`:
- `{lang}-v1-pair-2M`
- `{lang}-v1-hard-negatives-100k`

Schema:
- Pair configs: `query`, `pos`
- Hard-negative configs: `query`, `pos`, `negs` (list[string])

## Subsets And Row Counts (After Filter + Query Dedup + Pos Dedup)

Note: subset names keep the original `2M` / `100k` naming convention for compatibility, but
actual row counts vary by language and can be substantially lower after quality filtering and
deduplication.

| Subset (config name) | split | num_examples |
| --- | --- | ---: |
| `go-v1-pair-2M` | `train` | 1,532,319 |
| `go-v1-hard-negatives-100k` | `train` | 87,536 |
| `java-v1-pair-2M` | `train` | 1,456,651 |
| `java-v1-hard-negatives-100k` | `train` | 80,906 |
| `javascript-v1-pair-2M` | `train` | 1,298,745 |
| `javascript-v1-hard-negatives-100k` | `train` | 79,484 |
| `php-v1-pair-2M` | `train` | 1,311,302 |
| `php-v1-hard-negatives-100k` | `train` | 74,945 |
| `python-v1-pair-2M` | `train` | 1,779,891 |
| `python-v1-hard-negatives-100k` | `train` | 96,670 |
| `ruby-v1-pair-2M` | `train` | 1,145,414 |
| `ruby-v1-hard-negatives-100k` | `train` | 67,937 |

Total rows:
- Pair: 8,524,322
- Hard-negatives: 487,478
- Overall: 9,011,800

## Dedup Impact (Pos Dedup Stage)

The table below shows the `pos`-dedup impact on top of the previous filtered + query-deduped data.

| Subset | before | after | removed | removed_ratio |
| --- | ---: | ---: | ---: | ---: |
| `go-v1-pair-2M` | 1,541,111 | 1,532,319 | 8,792 | 0.57% |
| `go-v1-hard-negatives-100k` | 87,647 | 87,536 | 111 | 0.13% |
| `java-v1-pair-2M` | 1,491,655 | 1,456,651 | 35,004 | 2.35% |
| `java-v1-hard-negatives-100k` | 81,657 | 80,906 | 751 | 0.92% |
| `javascript-v1-pair-2M` | 1,310,965 | 1,298,745 | 12,220 | 0.93% |
| `javascript-v1-hard-negatives-100k` | 79,684 | 79,484 | 200 | 0.25% |
| `php-v1-pair-2M` | 1,343,442 | 1,311,302 | 32,140 | 2.39% |
| `php-v1-hard-negatives-100k` | 75,632 | 74,945 | 687 | 0.91% |
| `python-v1-pair-2M` | 1,807,480 | 1,779,891 | 27,589 | 1.53% |
| `python-v1-hard-negatives-100k` | 97,147 | 96,670 | 477 | 0.49% |
| `ruby-v1-pair-2M` | 1,175,219 | 1,145,414 | 29,805 | 2.54% |
| `ruby-v1-hard-negatives-100k` | 68,382 | 67,937 | 445 | 0.65% |

Stage totals:
- Pair removed by pos dedup: 145,550 (1.68%)
- Hard-negatives removed by pos dedup: 2,671 (0.54%)
- Overall removed by pos dedup: 148,221 (1.62%)

## Quick Usage

```python
from datasets import load_dataset

pair_ds = load_dataset("hotchpotch/cornstack-samples", "python-v1-pair-2M", split="train")
hard_ds = load_dataset("hotchpotch/cornstack-samples", "python-v1-hard-negatives-100k", split="train")

print(pair_ds.column_names, len(pair_ds))
print(hard_ds.column_names, len(hard_ds))
```

## License

This dataset follows CoRNStack and is released under **Apache-2.0**.

## Citation And Attribution

If you use this dataset, please cite and attribute CoRNStack:
- Paper: https://huggingface.co/papers/2412.01007
- Collection: https://huggingface.co/collections/nomic-ai/cornstack

## Noise Filtering Algorithm (Rule-based)

The following deterministic rules are applied before publishing this release.

1. Prefix-based noisy query removal
A row is dropped if `query` starts with any of the following prefixes:
- `TODO`
- `GET /`
- `POST /`
- `PUT /`
- `DELETE /`
- `Display a listing of the resource.`
- `Store a newly created resource in storage.`
- `Show the form for editing the specified resource.`
- `Update the specified resource in storage.`
- `Show the form for creating a new resource.`
- `Remove the specified resource from storage.`
- `Display the specified resource.`
- `Transform the resource into an array.`
- `Autogenerated method stub`
- `Auto generated`
- `this down() migration is autogenerated`
- `this up() migration is autogenerated`
- `"/ renamed from:"`
- `"/ access modifiers changed from:"`

2. Minimum positive-document length
A row is dropped if the positive side text is shorter than 30 characters.
- Pair configs: `pos` length >= 30 required
- Hard-negative configs: `pos` length >= 30 required

3. Hard-negative size constraint
For hard-negative configs in this release, each row keeps exactly seven negatives after normalization (`len(negs) = 7`, equivalent to `min_negs = 7`).

4. Query-level deduplication
Within each subset split, rows are grouped by exact `query` string.
- Keep the first occurrence
- Drop all later duplicates

5. Positive-document (`pos`) deduplication
Within each subset split, rows are grouped by exact `pos` string.
- Keep the first occurrence
- Drop all later duplicates

This filtering is purely rule-based (no model scoring), targeting high-noise templates and low-information positives while preserving broad retrieval coverage.