add limits and requests for cnpg

manifests/cnpg/cluster.yaml

@@ -7,6 +7,14 @@ spec:
   instances: 3
   imageName: ghcr.io/cloudnative-pg/postgresql:16
 
+  resources:
+    requests:
+      memory: 1Gi
+      cpu: 250m
+    limits:
+      memory: 2Gi
+      cpu: 1000m
+
   storage:
     size: 20Gi
     storageClass: yc-network-ssd
@@ -21,10 +29,13 @@ spec:
 
   postgresql:
     parameters:
-      shared_buffers: "256MB"
-      effective_cache_size: "768MB"
+      shared_buffers: "512MB"
+      effective_cache_size: "1536MB"
       maintenance_work_mem: "64MB"
       max_connections: "200"
+      work_mem: "16MB"
+      random_page_cost: "1.1"
+      effective_io_concurrency: "200"
 
   monitoring:
     enablePodMonitor: true