Returns the items of $sourceSeq in an
fn:unordered( $sourceSeq as item()*item()*The function returns the items of $sourceSeq in an implementation-dependent order.
The expression fn:unordered((1, 2, 3, 4, 5)) returns (1, 2, 3, 4, 5).
Query optimizers may be able to do a better job if the order of the output sequence is not specified. For example, when retrieving prices from a purchase order, if an index exists on prices, it may be more efficient to return the prices in index order rather than in document order.