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+---
+title: Set Appropriate Connection Limits
+impact: CRITICAL
+impactDescription: Prevent database crashes and memory exhaustion
+tags: connections, max-connections, limits, stability
+---
+
+## Set Appropriate Connection Limits
+
+Too many connections exhaust memory and degrade performance. Set limits based on available resources.
+
+**Incorrect (unlimited or excessive connections):**
+
+```sql
+-- Default max_connections = 100, but often increased blindly
+show max_connections;  -- 500 (way too high for 4GB RAM)
+
+-- Each connection uses 1-3MB RAM
+-- 500 connections * 2MB = 1GB just for connections!
+-- Out of memory errors under load
+```
+
+**Correct (calculate based on resources):**
+
+```sql
+-- Formula: max_connections = (RAM in MB / 5MB per connection) - reserved
+-- For 4GB RAM: (4096 / 5) - 10 = ~800 theoretical max
+-- But practically, 100-200 is better for query performance
+
+-- Recommended settings for 4GB RAM
+alter system set max_connections = 100;
+
+-- Also set work_mem appropriately
+-- work_mem * max_connections should not exceed 25% of RAM
+alter system set work_mem = '8MB';  -- 8MB * 100 = 800MB max
+```
+
+Monitor connection usage:
+
+```sql
+select count(*), state from pg_stat_activity group by state;
+```
+
+Reference: [Database Connections](https://supabase.com/docs/guides/platform/performance#connection-management)