element mp:db {
attribute path { xsd:string },
attribute uri { xsd:string },
element mp:db {
attribute path { xsd:string },
attribute uri { xsd:string },
element mp:prefix { xsd:string }+,
element mp:field { xsd:string }*,
element mp:criteria { xsd:string }*,
element mp:prefix { xsd:string }+,
element mp:field { xsd:string }*,
element mp:criteria { xsd:string }*,