Hi there, I'm currently porting some XQuery scripts to MonetDB/XQuery, and encountered two maybe simple obstacles. The first one is that I can't use fn:collection, but instead always have to apply pf:collection. The online documentation [1] states both alternatives should be practicable. For example in eXist and Sedna I can write: let $a := fn:collection("samples") return $a//id But this does not work for MonetDB/XQuery! Here I have to use: let $a := pf:collection("samples")/child::document-node() return $a//id My second question is that I cannot execute this kind of queries, which runs well in eXist and Sedna: <average> { fn:round(fn:avg( for $doc in fn:collection("samples") return $doc/example/@sum )) } </average> For MonetDB/XQuery I have to pull out pf:collection and add a second return statement: let $col := pf:collection("samples")/child::document-node() return <average> { fn:round(fn:avg( for $doc in $col return $doc/example/@sum )) } </average> So what am I doing wrong? Does MonetDB/XQuery by any chance comply more with any standards than eXist and Sedna do? Or ist fn:collection just not implemented in the current release of MonetDB/XQuery? I would be glad if someone could give me a hint! It's so confusing... Thank you! Regards, Andreas Meinl [1] http://monetdb.cwi.nl/projects/monetdb/XQuery/QuickTour/DOCMGT/ index.html#openall