# Performance Optimization

Singdata Lakehouse provides multi-level performance optimization capabilities covering query acceleration, storage optimization, index recommendations, and problem diagnostics — applicable to different performance bottleneck scenarios.

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## This Section

| Page | Description |
|------|------|
| [Result Cache](result_cache.md) | Query result caching: identical queries hit the cache directly without recomputation — ideal for high-frequency repeated queries |
| [Compute Cluster Cache](vc_cache.md) | Preload hot data to compute cluster local nodes to reduce object storage I/O latency; supports active caching (AP clusters) and passive caching (GP/AP clusters) |
| [Small File Optimization](small_file_optimization.md) | Automatically merge small files generated by high-frequency writes to reduce I/O during queries; suitable for high-frequency write scenarios like Dynamic Table refreshes |
| [Recommended Sorting Columns for Tables](auto-index.md) | The system automatically analyzes query filter conditions and recommends columns suitable for Sort Keys to speed up filter queries |
| [Job Profile](jobprofile-bestpractices.md) | View job history from the past 7 days, analyze slow queries and failed jobs, and identify performance bottlenecks |

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## Quick Selection Guide

**Query results don't change but every run recomputes from scratch**
→ Enable [Result Cache](result_cache.md) — identical SQL hits the cache directly

**BI report queries are slow and data is on object storage**
→ Use [Compute Cluster Cache](vc_cache.md) to actively preload hot tables to AP cluster local storage

**Queries slow down after Dynamic Table or high-frequency writes**
→ Enable [Small File Optimization](small_file_optimization.md) to merge fragmented files

**Not sure which columns should be Sort Keys**
→ Enable [Auto Index Recommendations](auto-index.md) — the system suggests based on actual query patterns

**Slow queries or errors with unknown causes**
→ Open [Job Profile](jobprofile-bestpractices.md) to view execution details and error information