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Showing posts with the label Database Optimization

Optimizing PostgreSQL JSONB: When to Use GIN vs. B-Tree Indexes

  One of the most pervasive anti-patterns in modern PostgreSQL usage is the reflex action of slapping a GIN index on a   JSONB   column the moment performance dips. While  JSONB  offers schema flexibility, treating it as a black box for indexing leads to severe write amplification, index bloat, and unpredictable latency spikes during high-throughput updates. Developers often assume GIN is the "JSON index," ignoring that for many access patterns—specifically deterministic value lookups—standard B-Tree indexes are vastly superior in size, write speed, and maintenance overhead. The Anatomy of the Performance Cost To understand why GIN (Generalized Inverted Index) kills write performance, you must understand how it stores data compared to the JSON document itself. 1. The Tokenization Explosion When you index a JSONB column with the default GIN operator class ( jsonb_ops ), PostgreSQL parses the  entire  JSON tree. It extracts every key and every value as s...