Added: Postgres 15; RPi Optimized

hosts/cyper-pi-1/postgres.nix

@@ -0,0 +1,65 @@
+{
+  pkgs,
+  ...
+}:
+
+{
+  services.postgresql = {
+    enable = true;
+    package = pkgs.postgresql_15;
+    port = 5432;
+
+    # Initial database setup
+    initialScript = pkgs.writeText "backend-init-script" ''
+      CREATE USER postgres WITH SUPERUSER PASSWORD 'postgres';
+    '';
+
+    # Raspberry Pi 4 optimized settings (2GB RAM assumed)
+    settings = {
+      # Memory settings (RPi 4 has limited RAM)
+      shared_buffers = "128MB";
+      effective_cache_size = "512MB";
+      maintenance_work_mem = "32MB";
+      work_mem = "2MB";
+      wal_buffers = "4MB";
+
+      # Connection settings
+      max_connections = 20;
+
+      # Performance tuning for ARM/RPi
+      random_page_cost = 2.0;
+      effective_io_concurrency = 100;
+
+      # WAL settings (conservative for SD card)
+      wal_level = "replica";
+      checkpoint_timeout = "15min";
+      checkpoint_completion_target = 0.7;
+      min_wal_size = "1GB";
+      max_wal_size = "4GB";
+
+      # Query planning
+      default_statistics_target = 50;
+
+      # Logging
+      log_min_duration_statement = 1000;
+      log_duration = false;
+
+      # ARM/RPi specific
+      cpu_index_tuple_cost = 0.1;
+      cpu_operator_cost = 0.05;
+    };
+  };
+
+  # Enable the PostgreSQL service to start on boot
+  systemd.services.postgresql.wantedBy = [ "multi-user.target" ];
+
+  # Create mount point for external USB storage (optional, for better performance)
+  # Uncomment if using the USB 3 storage we configured earlier
+  # systemd.tmpfiles.rules = [
+  #   "d /mnt/nix-storage/postgresql 0700 postgres postgres"
+  # ];
+
+  # environment.etc."postgresql/postgresql.conf".text = ''
+  #   data_directory = '/mnt/nix-storage/postgresql'
+  # '';
+}