I'm wading about in several tens of megabytes of health care data, trying to figure out what connects to which, as it were. There are a few thousand relationship elements that define some of the connections, and often more than one such element per @type, so it's not enough to just group them by _this_ relationship elements type, I need all the relationship elements which have a particular type value.
let $relationships as element(relationship)+ := //relationship[@type] let $relTypes as xs:string+ := distinct-values($relationships/@type/string()) let $relByType := map:merge(for $x in $relTypes return map:entry($x,$relationships[@type eq $x])) return $relByType
82895.5 ms
let $relationships as element(relationship)+ := //relationship[@type] let $relByType := map:merge(for $x in $relationships let $key := $x/@type group by $key return map:entry($key,$x)) return $relByType
170.79ms
Holy Wow.
Offered just in case anyone else is wondering why their query is so slow.
-- Graydon