XML sub-document versioning method in XML databases using record storages

A new sub-document versioning method for record storages of XML documents which uses virtual cutting points to ensure that a search tree is able to support multiple versions of sub-documents and provide efficient mechanisms for XML updating. Record boundaries and virtual cut points divide the two-dimensional space, the horizontal axis representing node identifiers in document order and vertical axis representing version numbers, into rectangles. The bottom corner of the rectangle is used to represent the rectangles and the corresponding information of the corner is added to the search tree index.