XMLTABLE ( [XMLNAMESPACES ( namespace_uri AS namespace_name [, ...] ), ] row_expression PASSING [BY {REF|VALUE}] document_expression [BY {REF|VALUE}] COLUMNS name { type [PATH column_expression] [DEFAULT default_expression] [NOT NULL | NULL] | FOR ORDINALITY } [, ...] ) → setof recordThe xmltable expression produces a table based on an XML value, an XPath filter to extract rows, and a set of column definitions. Although it syntactically resembles a function, it can only appear as a table in a query's FROM clause.