SQL Query and performance tuning - DB stats and identifying slow queries
📊 Understanding Table Statistics in PostgreSQL (With Simple Examples) Efficient queries depend on knowing your data . PostgreSQL uses table statistics to build better query plans, and you can use them too, to diagnose slow queries , analyze distributions , and optimize performance . Let’s explore how to gather and use these statistics using tools like: ANALYZE pg_stat_statements auto_explain pg_stats 📦 Why Do Table Statistics Matter? PostgreSQL keeps metadata about: 🔢 Number of rows in each table 💾 Storage usage 🔄 Value frequency (e.g., most common values) 📉 Data distribution (e.g., histograms, skew) ⚖️ Cardinality (how many distinct values a column has) This info helps the query planner decide how to execute your queries efficiently. ⚙️ 1. Collecting Stats with ANALYZE Run ANALYZE to gather statistics on tables: ANALYZE your_table; You can also combine it with VACUUM to clean and analyze at the same time: VACUUM ANALYZE your...