# Release Notes - v2.8.21

**Date**: 2026-01-18

## 📝 Executive Summary

```text
2.8.21 2026-01-18

- fix: remove contradictory query_cache_limit recommendation when disabling query cache (issue #671)
- fix: cap join_buffer_size recommendation at 4MB and prefer index optimization (issue #671)
- chore: bump version to 2.8.21
```

## 🛠️ Internal Commit History

Initial release or no previous tag found.

## ⚙️ Technical Evolutions

## ✅ Laboratory Verification Results

- [x] Automated TDD suite passed.
- [x] Multi-DB version laboratory execution validated.
- [x] Performance indicator delta analysis completed.
