Remove redundant index on clusters_kubernetes_namespaces

Changelog: other

db/post_migrate/20220201034731_remove_index_clusters_kubernetes_namespaces_on_cluster_id.rb

+# frozen_string_literal: true
+
+class RemoveIndexClustersKubernetesNamespacesOnClusterId < Gitlab::Database::Migration[1.0]
+  INDEX = 'index_clusters_kubernetes_namespaces_on_cluster_id'
+
+  disable_ddl_transaction!
+
+  def up
+    remove_concurrent_index_by_name :clusters_kubernetes_namespaces, INDEX
+  end
+
+  def down
+    add_concurrent_index :clusters_kubernetes_namespaces, :cluster_id, name: INDEX
+  end
+end

db/schema_migrations/20220201034731

+873ff811d4f70c012785297ee8c07eb496994af69d5ae4b266e8f675c88daca4
\ No newline at end of file

db/structure.sql

@@ -25989,8 +25989,6 @@ CREATE INDEX index_clusters_integration_elasticstack_enabled ON clusters_integra
 
 CREATE INDEX index_clusters_integration_prometheus_enabled ON clusters_integration_prometheus USING btree (enabled, created_at, cluster_id);
 
-CREATE INDEX index_clusters_kubernetes_namespaces_on_cluster_id ON clusters_kubernetes_namespaces USING btree (cluster_id);
-
 CREATE INDEX index_clusters_kubernetes_namespaces_on_cluster_project_id ON clusters_kubernetes_namespaces USING btree (cluster_project_id);
 
 CREATE INDEX index_clusters_kubernetes_namespaces_on_environment_id ON clusters_kubernetes_namespaces USING btree (environment_id);