sig
type physical_materialized_type = PT_CSeq | PT_LSeq
type physical_xml_type =
PT_Mat of Xquery_algebra_ast_annotation.physical_materialized_type
| PT_Sax
type physical_tuple_type =
(Xquery_common_ast.cvname *
Xquery_algebra_ast_annotation.physical_xml_type)
list
type physical_type =
PT_XML of Xquery_algebra_ast_annotation.physical_xml_type
| PT_Table of Xquery_algebra_ast_annotation.physical_tuple_type
end