avoiding statement cache if there are no bind values

activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb

@@ -521,6 +521,8 @@ module ActiveRecord
       end
 
       def exec(sql, name = 'SQL', binds = [])
+        return exec_no_cache(sql, name) if binds.empty?
+
         log(sql, name) do
           unless @statements.key? sql
             nextkey = "a#{@statements.length + 1}"
@@ -962,6 +964,15 @@ module ActiveRecord
         end
 
       private
+      def exec_no_cache(sql, name)
+        log(sql, name) do
+          result = @connection.async_exec(sql)
+          ret = ActiveRecord::Result.new(result.fields, result_as_array(result))
+          result.clear
+          ret
+        end
+      end
+
         # The internal PostgreSQL identifier of the money data type.
         MONEY_COLUMN_TYPE_OID = 790 #:nodoc:
         # The internal PostgreSQL identifier of the BYTEA data type.

activerecord/test/cases/adapters/postgresql/schema_authorization_test.rb

@@ -43,6 +43,18 @@ class SchemaAuthorizationTest < ActiveRecord::TestCase
     end
   end
 
+  def test_auth_with_bind
+    assert_nothing_raised do
+      set_session_auth
+      USERS.each do |u|
+        @connection.clear_cache!
+        set_session_auth u
+        assert_equal u, @connection.exec("SELECT name FROM #{TABLE_NAME} WHERE id = $1", 'SQL', [[nil, 1]]).first['name']
+        set_session_auth
+      end
+    end
+  end
+
   def test_schema_uniqueness
     assert_nothing_raised do
       set_session_auth