What is data-data-lake?

A guide to building data lakes: large stores of data held on cloud or object storage, often using Delta Lake, Apache Iceberg, or Apache Hudi. It covers reliable updates, history, schema changes, and storage organization.

It is for selecting a lake table format, planning partitions and compaction, supporting time-travel queries, and handling change-data-capture data with Spark, Flink, Trino, Presto, or Hive.

It helps make raw cloud-stored data reliable and queryable even when records are updated, schemas change, or data arrives continuously.

data-data-lake — Skill for Claude Code and Codex by j4flmao

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 j4flmao/agent-skills --skill data-lake

Clone the repo

git clone --depth 1 https://github.com/j4flmao/agent-skills

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.

README.md

[![agentmods](https://agentmods.dev/badge/skills/j4flmao/agent-skills/data-lake/github.svg)](https://agentmods.dev/skills/j4flmao/agent-skills/data-lake)

Your own site

<a href="https://agentmods.dev/skills/j4flmao/agent-skills/data-lake"><img src="https://agentmods.dev/badge/skills/j4flmao/agent-skills/data-lake/github.svg" alt="Measured on agentmods" height="20"></a>

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.

Your own site · 80×15

<a href="https://agentmods.dev/skills/j4flmao/agent-skills/data-lake"><img src="https://agentmods.dev/badge/skills/j4flmao/agent-skills/data-lake.svg" alt="Reviewed on agentmods" width="80" height="20"></a>

Per session 101 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.

When invoked 4,983 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. Third-party audits

NVIDIA SkillSpector pass 7 Sept 2026

How audits are shown

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.

Model	Per session	Once invoked
Fable 5.1	$0.00101	$0.04983
Opus 5	$0.00051	$0.02491
Sonnet 5	$0.00020	$0.00997
Haiku 4.5	$0.00010	$0.00498

Measured 8d ago against content hash 73b5658225f6, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-12, from the pricing page.

Security

Grade A, and why

data-data-lake 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 8d 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.

skills/data/data-lake/SKILL.md · 578 lines

How it starts

The opening of the file, as written. The whole thing — 578 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Data Lake

Purpose

Design and operate ACID-compliant data lakes on object storage using Delta Lake, Apache Iceberg, or Apache Hudi. Manage table formats, optimize storage layout, enforce schema evolution, and implement time-travel and CDC patterns.

Agent Protocol

Trigger

Exact user phrases: "Delta Lake", "Apache Iceberg", "Apache Hudi", "Lakehouse", "ACID on lake", "time travel", "table format", "compaction", "Z-order", "Hilbert curve", "vacuum", "CDC", "merge-on-read", "copy-on-write", "manifest file", "metadata layer", "schema evolution", "optimize table", "incremental query".

Input Context

Before activating, verify:

Object storage backend (S3, ADLS, GCS, MinIO)
Table format preference (Delta, Iceberg, Hudi)
Compute engine (Spark, Flink, Trino, Presto, Hive)
Write pattern (append-heavy, update-heavy, CDC stream)
Query pattern (OLAP, incremental, point lookup, full scan)
Partition strategy (date, categorical, Z-order dimensions)

Output Artifact

Lake architecture with table format selection, compaction strategy, optimization plan.

Response Format

Table Format: {Delta Lake | Apache Iceberg | Apache Hudi}
Storage: {S3 | ADLS | GCS | MinIO}
Write Mode: {copy-on-write | merge-on-read}
Partition: {column, granularity}
Optimize: {Z-order by columns, compaction interval}
Vacuum: {retention hours}

-- DDL / optimization commands

No preamble. No postamble. No explanations. No filler/hedging/transitions. Compress output — why use many token when few do trick.

Completion Criteria

Table format selected with trade-off analysis
ACID guarantees documented (concurrent readers/writers)
Write mode (CoW vs MoR) selected per table
Partition strategy defined
Compaction policy set (file size target, interval)
Vacuum retention period configured
Schema evolution rules defined

Max Response Length

250 lines of config.

Workflow

Step 1: Select Table Format

Format Comparison Matrix

Read the full file on GitHub · 578 lines

Files

What ships with it

32 files beside SKILL.md in the same directory: the scripts, references and assets a skill reads on demand. Not counted in the per-session cost; read them before you install if any of them is executable.

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.

8d ago First seen · 578 lines · 101 tokens per session scan A 73b5658225f6

Subscribe to this mod's changes

data-data-lake is a skill published in the GitHub repository j4flmao/agent-skills (23 stars, last pushed 6d ago), licensed MIT. It adds 101 tokens to every session and 4,983 once invoked, about $0.0005 per session on Opus 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 2026-09-03.

Analytics and metrics Databases data lake phase-11 storage

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data-data-lake