Hi Djoerd, from http://www.w3.org/TR/xpath20/ ======== [...] 3.2.2 Predicates [...] Note: When using predicates with a sequence of nodes selected using a reverse axis, it is important to remember that the the context positions for such a sequence are assigned in reverse document order. For example, preceding::foo[1] returns the first qualifying foo element in reverse document order, because the predicate is part of an axis step using a reverse axis. By contrast, (preceding::foo)[1] returns the first qualifying foo element in document order, because the parentheses cause (preceding::foo) to be parsed as a primary expression in which context positions are assigned in document order. Similarly, ancestor::*[1] returns the nearest ancestor element, because the ancestor axis is a reverse axis, whereas (ancestor::*)[1] returns the root element (first ancestor in document order). [...] ======= i.e., (IMHO) MonetDB/XQuery 0.18 was wrong, MonetDB/XQuery 0.22 is right. Stefan On Tue, Feb 19, 2008 at 11:55:26PM +0100, Djoerd Hiemstra wrote:

Hi there MonetDBs,

The results for the following query changed between v0.18 and v0.22:

let $list := <list> <item>1</item> <item>2</item> <item>3</item> <item>4</item> </list> return $list//item[. = "4"]/preceding-sibling::*[1]

It now gives item 3, which I think is wrong since the results of any axis step (also preceding-sibling), should be in document order. The result in version 0.18 is item 1.

Best, Djoerd.

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