Merge pull request #40876 from fsateler/performance/type-map-initialize

postgres: Make the initial type map query less expensive

activerecord/lib/active_record/connection_adapters/postgresql/oid/type_map_initializer.rb

@@ -33,15 +33,27 @@ module ActiveRecord
             composites.each { |row| register_composite_type(row) }
           end
 
-          def query_conditions_for_initial_load
+          def query_conditions_for_known_type_names
             known_type_names = @store.keys.map { |n| "'#{n}'" }
-            known_type_types = %w('r' 'e' 'd')
+            <<~SQL % known_type_names.join(", ")
-            <<~SQL % [known_type_names.join(", "), known_type_types.join(", ")]
               WHERE
                 t.typname IN (%s)
-                OR t.typtype IN (%s)
+            SQL
-                OR t.typinput = 'array_in(cstring,oid,integer)'::regprocedure
+          end
-                OR t.typelem != 0
+
+          def query_conditions_for_known_type_types
+            known_type_types = %w('r' 'e' 'd')
+            <<~SQL % known_type_types.join(", ")
+              WHERE
+                t.typtype IN (%s)
+            SQL
+          end
+
+          def query_conditions_for_array_types
+            known_type_oids = @store.keys.reject { |k| k.is_a?(String) }
+            <<~SQL % [known_type_oids.join(", ")]
+              WHERE
+                t.typelem IN (%s)
             SQL
           end
 

activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb

@@ -624,21 +624,25 @@ module ActiveRecord
 
         def load_additional_types(oids = nil)
           initializer = OID::TypeMapInitializer.new(type_map)
+          load_types_queries(initializer, oids) do |query|
+            execute_and_clear(query, "SCHEMA", []) do |records|
+              initializer.run(records)
+            end
+          end
+        end
 
+        def load_types_queries(initializer, oids)
           query = <<~SQL
             SELECT t.oid, t.typname, t.typelem, t.typdelim, t.typinput, r.rngsubtype, t.typtype, t.typbasetype
             FROM pg_type as t
             LEFT JOIN pg_range as r ON oid = rngtypid
           SQL
-
           if oids
-            query += "WHERE t.oid IN (%s)" % oids.join(", ")
+            yield query + "WHERE t.oid IN (%s)" % oids.join(", ")
           else
-            query += initializer.query_conditions_for_initial_load
+            yield query + initializer.query_conditions_for_known_type_names
-          end
+            yield query + initializer.query_conditions_for_known_type_types
-
+            yield query + initializer.query_conditions_for_array_types
-          execute_and_clear(query, "SCHEMA", []) do |records|
-            initializer.run(records)
           end
         end