fabric-lakehouse-perf-remediate

fabric-lakehouse-perf-remediate is a skill for Claude Code, Codex from PatrickGallucci/fabric-skills. It costs 117 tokens per session (2,331 once invoked), scanned A, original, MIT.

A troubleshooting guide for Microsoft Fabric Lakehouse data systems. A Lakehouse stores data in tables and files so it can be processed with Spark and queried for analysis.

In plain words
What is it for?
Use it to inspect and improve Spark jobs, Delta tables, SQL analytics endpoint queries, Direct Lake reports, table maintenance, streaming ingestion, and Fabric capacity settings.
Why use it?
It helps identify why queries, data jobs, or reports are slow, including too many small files, fragmented tables, inefficient queries, limited computing capacity, or concurrency problems.

Skill for Claude CodeCodex

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

Good fit Use it to inspect and improve Spark jobs, Delta tables, SQL analytics endpoint queries, Direct Lake reports, table maintenance, streaming ingestion, and Fabric capacity settings.

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Install with agentmods
npx agentmods add skills/patrickgallucci/fabric-skills/fabric-lakehouse-perf-remediate
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 PatrickGallucci/fabric-skills --skill fabric-lakehouse-perf-remediate
Clone the repo
git clone --depth 1 https://github.com/PatrickGallucci/fabric-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.

agentmods badge for fabric-lakehouse-perf-remediate

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.

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Your own site · 80×15
<a href="https://agentmods.dev/skills/patrickgallucci/fabric-skills/fabric-lakehouse-perf-remediate"><img src="https://agentmods.dev/badge/skills/patrickgallucci/fabric-skills/fabric-lakehouse-perf-remediate.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 117 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 2,331 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 $0.00117 $0.02331
Opus 5 $0.00059 $0.01166
Sonnet 5 $0.00023 $0.00466
Haiku 4.5 $0.00012 $0.00233

Measured 12d ago against content hash 2e52dad09c2c, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-12, from the pricing page.

Security

Grade A, and why

fabric-lakehouse-perf-remediate 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 12d ago.

The scan reads SKILL.md. This mod also ships 4 executable files (scripts/Get-DeltaTableHealth.ps1, scripts/Invoke-FabricTableMaintenance.ps1, templates/maintenance-notebook.py, …), listed below but not scanned — reading those needs a real analyzer, not pattern matching.

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/fabric-lakehouse-perf-remediate/SKILL.md · 238 lines

How it starts

The opening of the file, as written. The whole thing — 238 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Fabric Lakehouse Performance remediate

Systematic toolkit for diagnosing and resolving performance issues in Microsoft Fabric Lakehouse environments. Covers Delta table health, Spark compute tuning, query optimization, and automated maintenance workflows.

When to Use This Skill

  • Lakehouse queries are running slowly or timing out
  • Delta tables have accumulated many small files (small file problem)
  • Spark notebooks or jobs are underperforming
  • Direct Lake semantic models have cold-start or transcoding delays
  • SQL analytics endpoint queries are slow
  • Table maintenance (OPTIMIZE, VACUUM) needs to be scheduled or automated
  • V-Order, Z-Order, or resource profile configuration is needed
  • Capacity throttling or concurrency issues are suspected
  • Streaming ingestion is creating fragmented Delta tables

Prerequisites

  • Microsoft Fabric workspace with Lakehouse items
  • Contributor or higher workspace role
  • Fabric capacity (F2 or above) or Trial capacity
  • For REST API automation: Microsoft Entra token for Fabric service
  • For Spark commands: Access to Fabric notebooks or Spark Job Definitions

Quick Diagnosis Checklist

When a user reports Lakehouse performance issues, work through these areas in order:

  1. Identify the symptom — Slow reads, slow writes, capacity throttling, or query timeouts
  2. Check Delta table health — File count, file sizes, V-Order status, partition layout
  3. Review Spark configuration — Resource profile, autotune, shuffle partitions
  4. Inspect capacity utilization — Concurrency limits, burst capacity, throttling
  5. Evaluate maintenance history — When was OPTIMIZE/VACUUM last run?
  6. Assess data patterns — Streaming vs batch, read-heavy vs write-heavy

Symptom-to-Action Map

Symptom Root Cause Action
Slow reads across all engines Small files, no V-Order Run OPTIMIZE VORDER, switch to readHeavy profile
Slow Spark queries only Wrong shuffle partitions Enable autotune or tune manually
Slow Power BI Direct Lake Too many Parquet files/row groups Run OPTIMIZE, check guardrail limits
Slow SQL analytics endpoint Files under 400 MB, too many small files OPTIMIZE with maxRecordsPerFile=2M
Write performance degraded V-Order enabled on write-heavy workload Switch to writeHeavy resource profile
Capacity throttled Too many concurrent Spark jobs Review concurrency limits, enable optimistic admission
Storage growing unexpectedly VACUUM not running Schedule VACUUM with 7-day retention
Streaming creates tiny files No batching or trigger interval Add processingTime trigger, run periodic OPTIMIZE

Read the full file on GitHub · 238 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. 12d ago First seen · 238 lines · 117 tokens per session scan A 2e52dad09c2c

Subscribe to this mod's changes

fabric-lakehouse-perf-remediate is a skill published in the GitHub repository PatrickGallucci/fabric-skills (16 stars, last pushed 3mo ago), licensed MIT. It adds 117 tokens to every session and 2,331 once invoked, about $0.0006 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 2026-08-30.

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