Может быть полезно что-то вроде этого
select object_name(object_id) as TableName,
col_name(object_id, column_id) as ColumnName
from sys.column_xml_schema_collection_usages as U
inner join sys.xml_schema_collections as S
on U.xml_collection_id = S.xml_collection_id
where S.name = 'YourXMLSchemaCollectionName'
Это поможет вам найти, где схема используется в параметре XML.
select object_name(object_id)
from sys.parameter_xml_schema_collection_usages as P
inner join sys.xml_schema_collections as S
on P.xml_collection_id = S.xml_collection_id
where S.name = 'YourXMLSchemaCollectionName'