Thank you for the fast answer. Actually, using a non-updating expression is exactly what I did, except that validation is done in the calling application, as validate:xsd(...) merely supports a single schema. So it results in 2 queries, one non-updating query performing the update operations before validation and a second one that performs the "real" update after validation was successful. Are there plans to extend validate:xsd(...) to support multiple schemas in upcoming releases?
I am not quite sure if that's really a necessary requirement. Have you tried to execute validate:xsd multiple times in one query?
C.