memlayers-data v1

The frozen training bundle for a study of what memory-layer values store and how they are organized (PKM / PEER against a kNN-LM store), COMS E6998 Algorithms in LLMs. Code that builds, verifies and reads it: RoieGilad7/memory-layers-analysis, tag data-v1.

One bundle, three parts.

1. A 150M-token training slice of the Pile — monology/pile-uncopyrighted at revision 3be90335b66f24456a5d6659d9c8d208c0357119, five subjects at exactly 27,000,000 GPT-2 tokens each: Pile-CC, Github, PubMed Central, FreeLaw, Wikipedia (en).
2. Six held-out subjects, each split into a label half and a test half — the five above plus USPTO Backgrounds, which never appears in training at all, so it measures a subject the model has never seen. Every half is within 1% of 2,500,000 tokens per subject; the halves share no documents and no document ids with the training split.
3. Synthetic biographies of 2,500 fictional people — five facts each (birth date, birth city, university, major, employer) drawn uniformly at random from fixed value lists, so a model can only answer a question about one by having stored it. 2,000 people appear in training at one of three exposure tiers (frequent / normal / rare) and 500 are controls that never appear, which is the guessing floor. 8,000 distinct biographies, 190,000 copies, 15,142,237 tokens (10.06% of train.bin), and 100,000 fact-recall prompts.

train.bin is 150,475,264 GPT-2 tokens / 293,897 sequences of 512.

Licensing and provenance

• Upstream license tag: other. This bundle is a derived slice of monology/pile-uncopyrighted, which is EleutherAI's The Pile with the Books3, BookCorpus2, OpenSubtitles, YTSubtitles and OWT2 subsets removed — per that dataset's card, the subsets "not explicitly allowed to be used in AI training" according to the original Pile paper. It was published "in response to authors demanding that LLMs stop using their works".
• Component documents keep their own original licenses. The Pile is a compilation of many sources; nothing here relicenses any of them. Consult the upstream dataset card and the Pile paper before redistributing or using the Pile-derived files for anything beyond research reproduction.
• Pile text here is cleaned, deduplicated, split and tokenized, not reproduced verbatim as published: see reports/ in the bundle and the data reports in the code repository for exactly what was done.
• The biographies are synthetic. Every person, name and fact is generated by data/bios.py from a seed. They describe nobody. Candidate names are rejected if they occur in the Pile text or if a name word would hand a probe one of its answers.
• No part of this bundle is intended for training a model that is deployed; it exists so one experiment can be reproduced token for token.

Files

path	files	size	what
tokens/	2	304.1 MB	train.bin (uint16 GPT-2 ids) + train.idx.parquet, the segment index
heldout/	16	103.7 MB	label.bin, test.bin, their indexes, and the per-subject cleaned documents of each half
train/	5	227.2 MB	the cleaned, deduplicated training documents, one .jsonl.gz per subject
heldout_pool/	6	59.3 MB	the pool each held-out half was drawn from
bios/	8	58.7 MB	people.jsonl, bios_train.jsonl, bios_control.jsonl, facts.jsonl (100,000 prompts), the value lists, the templates, the name check
samples/	5	0.6 MB	the hand-check pack: Pile samples, biographies with every prompt, the value lists, and templates_rendered.md — all 120 sentence frames rendered twice
reports/	5	0.03 MB	what each build stage did: extraction, dedup, split, pack
raw/	12	398.0 MB	the archived source text a rebuild needs. Optional — data.fetch skips it unless you ask
manifest.json, validation_report.{json,md}	3	0.05 MB	the file list with a sha256 per file, and the A1–A18 results

59 hashed files, 1,151,617,170 bytes (753,606,445 without raw/).

How to verify your copy

The code repository carries the manifest, so verification does not trust this repo's copy of it:

git clone https://github.com/RoieGilad7/memory-layers-analysis
cd memory-layers-analysis
git checkout data-v1
pip install -r requirements.txt

# download (skips raw/ by default; --with-raw includes it) and check every sha256
python -m data.fetch --version v1

# or check a copy you already have, without downloading
python -m data.fetch --version v1 --verify-only

data.fetch hashes every file against data/manifests/v1.json and exits non-zero on any mismatch. The bundle's identity is its data_sha256, taken over the manifest's file list alone:

train.bin    sha256 7e3d50f2513d5a1b42c4fbf201ad4811e81e3175f41068277cf708f191bad8ac
bundle  data_sha256 bb1bfd407af2c44e86d020df1c075f8764c5bf6979be2835684f6f0453086fd6

Use the data-v1 tag, here and in the code repository, to get this exact bundle.

Checks

python -m data.validate --config configs/data/v1.yaml runs 18 checks on the real build, all of which pass for this bundle: byte-identical rebuild, every file's hash, exact per-subject token counts, subject shares inside every 1M window, format and index tiling, decode-back-to-source, train/held-out leakage (ids, exact hashes, 13-gram overlap), the halves' disjointness, no held-out-only subject in training, subject labels against the source, a bag-of-words subject classifier, the biography facts and their uniformity, no answer leaks in any of the 100,000 prompts, exposure counts and control isolation, the probe floor for a random scorer and an untrained model, the loader's order and resume, a per-subject unigram baseline, and a 2-hour learnability run.

The learnability run is the one result worth quoting here: after 5,830 steps on this data, a small PKM model recalls the frequent-tier facts 40.5% of the time as the top-1 answer against a 0.63% control floor — 64× — and recall is monotone across the exposure tiers. A structurally new wording of the same question recovers the fact only ~2% of the time, which is the finding the study is about.

Citation

@misc{memlayers_data_v1,
  title  = {memlayers-data v1: a controlled slice of the Pile with synthetic biographies},
  author = {Roie Gilad},
  year   = {2026},
  note   = {COMS E6998 Algorithms in LLMs final project. data\_sha256
            bb1bfd407af2c44e86d020df1c075f8764c5bf6979be2835684f6f0453086fd6},
  url    = {https://huggingface.co/datasets/roieg/memlayers-data}
}