2 files changed, 35 insertions, 37 deletions
diff --git a/activerecord/lib/active_record/connection_adapters/postgresql/column.rb b/activerecord/lib/active_record/connection_adapters/postgresql/column.rb
index 3ccc7271ab..ef98d2b37a 100644
--- a/activerecord/lib/active_record/connection_adapters/postgresql/column.rb
+++ b/activerecord/lib/active_record/connection_adapters/postgresql/column.rb
@@ -2,42 +2,21 @@
 
 module ActiveRecord
   module ConnectionAdapters
-    # PostgreSQL-specific extensions to column definitions in a table.
-    class PostgreSQLColumn < Column #:nodoc:
-      delegate :array, :oid, :fmod, to: :sql_type_metadata
-      alias :array? :array
-
-      def initialize(*, max_identifier_length: 63, **)
-        super
-        @max_identifier_length = max_identifier_length
-      end
-
-      def serial?
-        return unless default_function
-
-        if %r{\Anextval\('"?(?<sequence_name>.+_(?<suffix>seq\d*))"?'::regclass\)\z} =~ default_function
-          sequence_name_from_parts(table_name, name, suffix) == sequence_name
+    module PostgreSQL
+      class Column < ConnectionAdapters::Column # :nodoc:
+        delegate :array, :oid, :fmod, to: :sql_type_metadata
+        alias :array? :array
+
+        def initialize(*, serial: nil, **)
+          super
+          @serial = serial
         end
-      end
 
-      private
-        attr_reader :max_identifier_length
-
-        def sequence_name_from_parts(table_name, column_name, suffix)
-          over_length = [table_name, column_name, suffix].map(&:length).sum + 2 - max_identifier_length
-
-          if over_length > 0
-            column_name_length = [(max_identifier_length - suffix.length - 2) / 2, column_name.length].min
-            over_length -= column_name.length - column_name_length
-            column_name = column_name[0, column_name_length - [over_length, 0].min]
-          end
-
-          if over_length > 0
-            table_name = table_name[0, table_name.length - over_length]
-          end
-
-          "#{table_name}_#{column_name}_#{suffix}"
+        def serial?
+          @serial
         end
+      end
     end
+    PostgreSQLColumn = PostgreSQL::Column # :nodoc:
   end
 end
diff --git a/activerecord/lib/active_record/connection_adapters/postgresql/schema_statements.rb b/activerecord/lib/active_record/connection_adapters/postgresql/schema_statements.rb
index 41d1a8e4ab..5f27cb0793 100644
--- a/activerecord/lib/active_record/connection_adapters/postgresql/schema_statements.rb
+++ b/activerecord/lib/active_record/connection_adapters/postgresql/schema_statements.rb
@@ -650,16 +650,19 @@ module ActiveRecord
             default_value = extract_value_from_default(default)
             default_function = extract_default_function(default_value, default)
 
-            PostgreSQLColumn.new(
+            if match = default_function&.match(/\Anextval\('"?(?<sequence_name>.+_(?<suffix>seq\d*))"?'::regclass\)\z/)
+              serial = sequence_name_from_parts(table_name, column_name, match[:suffix]) == match[:sequence_name]
+            end
+
+            PostgreSQL::Column.new(
               column_name,
               default_value,
               type_metadata,
               !notnull,
-              table_name,
               default_function,
-              collation,
+              collation: collation,
               comment: comment.presence,
-              max_identifier_length: max_identifier_length
+              serial: serial
             )
           end
 
@@ -675,6 +678,22 @@ module ActiveRecord
             PostgreSQLTypeMetadata.new(simple_type, oid: oid, fmod: fmod)
           end
 
+          def sequence_name_from_parts(table_name, column_name, suffix)
+            over_length = [table_name, column_name, suffix].sum(&:length) + 2 - max_identifier_length
+
+            if over_length > 0
+              column_name_length = [(max_identifier_length - suffix.length - 2) / 2, column_name.length].min
+              over_length -= column_name.length - column_name_length
+              column_name = column_name[0, column_name_length - [over_length, 0].min]
+            end
+
+            if over_length > 0
+              table_name = table_name[0, table_name.length - over_length]
+            end
+
+            "#{table_name}_#{column_name}_#{suffix}"
+          end
+
           def extract_foreign_key_action(specifier)
             case specifier
             when "c"; :cascade