feat: Postgres max connections (#7067)

docker/middleware.env.example

@@ -9,6 +9,35 @@ POSTGRES_DB=dify
 # postgres data directory
 PGDATA=/var/lib/postgresql/data/pgdata
 
+# Maximum number of connections to the database
+# Default is 100
+#
+# Reference: https://www.postgresql.org/docs/current/runtime-config-connection.html#GUC-MAX-CONNECTIONS
+POSTGRES_MAX_CONNECTIONS=100
+
+# Sets the amount of shared memory used for postgres's shared buffers.
+# Default is 128MB
+# Recommended value: 25% of available memory
+# Reference: https://www.postgresql.org/docs/current/runtime-config-resource.html#GUC-SHARED-BUFFERS
+POSTGRES_SHARED_BUFFERS=128MB
+
+# Sets the amount of memory used by each database worker for working space.
+# Default is 4MB
+#
+# Reference: https://www.postgresql.org/docs/current/runtime-config-resource.html#GUC-WORK-MEM
+POSTGRES_WORK_MEM=4MB
+
+# Sets the amount of memory reserved for maintenance activities.
+# Default is 64MB
+#
+# Reference: https://www.postgresql.org/docs/current/runtime-config-resource.html#GUC-MAINTENANCE-WORK-MEM
+POSTGRES_MAINTENANCE_WORK_MEM=64MB
+
+# Sets the planner's assumption about the effective cache size.
+# Default is 4096MB
+#
+# Reference: https://www.postgresql.org/docs/current/runtime-config-query.html#GUC-EFFECTIVE-CACHE-SIZE
+POSTGRES_EFFECTIVE_CACHE_SIZE=4096MB
 
 # ------------------------------
 # Environment Variables for sandbox Service