handle-large-data-files

handle-large-data-files is a skill for Claude Code, Codex from DataSQRL/sqrl. It costs 48 tokens per session (655 once invoked), scanned A, original, Apache-2.0.

A workflow for handling large data files that slow or block DataSQRL compilation and tests. It first examines the file, then samples it or excludes it depending on whether it is needed as connector data.

In plain words
What is it for?
Sampling large CSV, JSON, compressed, Parquet, ORC, or Avro files, or renaming files that should not be included in compilation.
Why use it?
DataSQRL copies recognized data files into its build area on every run, so large files can cause timeouts or a large-data block. This workflow keeps test inputs small while preserving a usable format.

Skill for Claude CodeCodex

Written for no agent in particular: nothing here depends on one.

Good fit Sampling large CSV, JSON, compressed, Parquet, ORC, or Avro files, or renaming files that should not be included in compilation.

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Install with agentmods
npx agentmods add skills/datasqrl/sqrl/handle-large-data-files
Install

Getting it into your agent

One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.

Any agent
npx skills add DataSQRL/sqrl --skill handle-large-data-files
Clone the repo
git clone --depth 1 https://github.com/DataSQRL/sqrl

Made for: Claude Code, Codex.

Wrote this? Show the measurements

A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.

agentmods badge for handle-large-data-files

README.md
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Your own site
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Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.

agentmods 80×15 button for handle-large-data-files

Your own site · 80×15
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Per session 48 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 655 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe.
Origin original No closer match found in the catalogue.
Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

ModelPer sessionOnce invoked
Fable 5.1 $0.00048 $0.00655
Opus 5.5 $0.00019 $0.00262
Sonnet 5.5 $0.00010 $0.00131
Haiku 4.5 $0.00005 $0.00065

Measured 10d ago against content hash 794189373853, method: parsed. Prices are Anthropic first-party input rates as of 2026-10-07, from the pricing page.

Security

Grade A, and why

handle-large-data-files scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 10d ago.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Nothing flagged

None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.

agent/skills/handle-large-data-files/SKILL.md · 34 lines

How it starts

The opening of the file, as written. The whole thing — 34 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Handle large data files

DataSQRL copies every recognized data file (.csv, .csv.gz, .json, .jsonl, .parquet, .orc, .avro, ...) found anywhere in the project into Flink's build/ data directory on every compile and test — with no cache. A large file (tens of MB or more) therefore makes every run slow and can exceed the test timeout. compile/test is blocked while such a file is present (LARGE_DATA_BLOCKED).

Renaming a file to *.bak removes it from the copy: the compiler recognizes files by data extension, and .bak is not one, so a .bak file is skipped — and it no longer triggers the block.

For each large file, first invoke the /data-observation skill and observe it (so you understand its schema and values), then classify and act.

Steps to follow

(a) The file is data a connector reads

Replace it with a small, coherent sample and point the connector at the sample.

  1. Produce a small sample (<1000 rows), keeping the same format so the connector's 'format' still matches:
    • For .jsonl / .csv files, use head -1000 big.jsonl > sample.jsonl command
    • For .csv.gz files, use zcat big.csv.gz | head -1000 | gzip > sample.csv.gz command
    • For .parquet files, use duckdb -c "COPY (SELECT * FROM 'big.parquet' LIMIT 1000) TO 'sample.parquet' (FORMAT PARQUET)" command
  2. Sample coherently across related files. When files reference each other (foreign keys), sample a consistent set of keys so references still resolve — otherwise the sampled test data has orphaned references. Pick a set of parent keys first, then keep only the child rows for those keys.
  3. Point the connector's path at the sample file. If you sampled into a different format than the original (e.g. parquet → jsonl), also update the connector's 'format' (and any format-specific options) to match — the 'format' key is independent of the file extension.
  4. Rename the original large file to *.bak so it is not copied, and delete any copy already written under build/.

Read the full file on GitHub · 34 lines

Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

  1. 10d ago First seen · 34 lines · 48 tokens per session scan A 794189373853

Subscribe to this mod's changes

handle-large-data-files is a skill published in the GitHub repository DataSQRL/sqrl (230 stars, last pushed today), licensed Apache-2.0. It adds 48 tokens to every session and 655 once invoked, about $0.0002 per session on Opus 5.5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-09-30.