fabric-lakehouse-perf-remediatelisted

# 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 partit