An XML schema that is registered in the XML
schema repository (XSR)
can be evolved into a new, compatible XML schema without the need for already
stored XML instance documents to be validated again. Only the XML schema as
registered in the XSR is updated; the stored XML instance documents, including
their URI identifiers, remain unchanged.
Before you begin
Before a schema can be evolved, the new XML schema
must be compatible with the original one. If the two schemas are not compatible,
the XSR_UPDATE stored procedure or the UPDATE XMLSCHEMA command will return
an error and no schema evolution takes place. See
Compatibility
requirements for evolving an XML schema.
About this task
To evolve an XML schema in the XSR:
Procedure
- Call the XSR_REGISTER stored procedure or run the REGISTER XMLSCHEMA
command to register the new XML schema in the XSR.
- Finally, call the XSR_UPDATE stored procedure or run the UPDATE
XMLSCHEMA command to update the new XML schema in the XSR.
What to do next
Successful schema evolution replaces the original XML schema. Once
evolved, only the updated XML schema is available.