XML schema evolutions can be performed on an XML-type database using partial data copy techniques. The partial data copy techniques provide mechanisms to identify a minimal set of data in the database that needs be copied out in order for schema evolution operations to occur. Identifying the minimal set of data involves comparing an existing XML schema to a new XML schema and determining the differences between the two schemas. Based on those differences, a minimal set of data can be determined. That data can then be copied to a temporary storage location, while the XML schema and its associated database structure are updated to conform to the new XML schema. Then, the minimal set of data is copied back into the modified database structure.