PostgreSQL JSONB Performance Optimization
A Comprehensive Survey
陈永源 225002025
The TOAST Threshold Problem
The 2KB Critical Threshold
- Before TOAST: Constant access time
- After TOAST: Linear degradation
- 3 additional buffer reads per access
JSONB Operator Performance
Partial Update Challenges
Current Limitations
- TOAST treats JSONB as atomic BLOB
- Full document rewrites for small changes
- WAL write amplification
Emerging Solutions
- Partial decompression: 5-10x faster
- In-place updates: 10-50x improvement
- Shared TOAST: 90% WAL reduction
Advanced Optimization Techniques
PostgreSQL JSONB vs MongoDB
