XQuery Update - unordered collection of update primitives

"TAN Kuan Hui" <[email protected]> Mon, 30 Jan 2006 21:07:05 +0800
Newsgroups gmane.comp.web.query-languages
Organization Xemantics Software Pte Ltd
Message-ID <000e01c6259e$2c60f510$6502a8c0@pinecone>
Section 2.1, Extensions to the Processing Model, carries the following
definition.

[Definition: A pending update list is an unordered collection of update primitives, which represent node state changes that have not
yet been applied.]

What is the significance of an <<unordered>> collection of update primitives ?
How is updating integrity preserved with an unordered collection of update
instructions ? I could not find an explicit description on the above and
would appreciate clarifications.

Thank you.

Kuan Hui