fn:unordered
Indicates that order is not significant, to improve performance
Description
The fn:unordered function indicates that order is not significant, to improve performance. In cases where the order of the results does not matter, the processor may be much more efficient if it does not have to keep track of order. This is especially true for FLWORs that perform joins. For example, processing multiple variable bindings in a for clause might be significantly faster if the processor can decide which variable binding controls the join without regard to the order of the results. A query author can tell the processor that order does not matter by enclosing an expression in a call to the fn:unordered function.
This description is © Copyright 2007, Priscilla Walmsley. It is excerpted from the book XQuery by Priscilla Walmsley, O'Reilly, 2007. For a complete explanation of this function, please refer to Appendix A of the book.
Arguments and Return Type
| Name | Type |
|---|---|
$sourceSeq |
item()* |
| return value | item()* |
History
| Published On | Last Updated | Contributor(s) |
|---|---|---|
| 2006-06-27 | 2007-02-26 | W3C, XQuery 1.0 and XPath 2.0 Functions and Operators, http://www.w3.org/TR/xpath-functions/ |
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