I wrote this way back before path indexes: http://www.xqueryhacker.com/2012/03/03/computed-indexes-in-marklogic.html
I really like the idea of giving path indexes an alias, and supporting more xpath like your example. Rob From: Geert Josten <[email protected]<mailto:[email protected]>> Reply-To: MarkLogic Developer Discussion <[email protected]<mailto:[email protected]>> Date: Monday, 14 April 2014 04:05 To: 'MarkLogic Developer Discussion' <[email protected]<mailto:[email protected]>> Subject: Re: [MarkLogic Dev General] date and dateTime comparison Interesting thought. Might be an extension to the path indexes, allowing something like: //myDateTime/xs:year(xs:dateTime(replace(., ' ', 'T'))) And if path index would be given names, then the difference between Fields and Paths becomes even smaller.. ;-) Grtz Van: [email protected]<mailto:[email protected]> [mailto:[email protected]] Namens Holger APEL Verzonden: maandag 14 april 2014 13:02 Aan: MarkLogic Developer Discussion Onderwerp: Re: [MarkLogic Dev General] date and dateTime comparison I’d support an RFE! We had a similar use case. We only wanted to use the year of a date field to build a facet and had to create an extra element with the year value. Our thinking was to have function based indexes. It could work a bit like fields with the difference that you are allowed to define expressions on elements rather than list of elements only. Regards, Holger From:[email protected]<mailto:[email protected]> [mailto:[email protected]] On Behalf Of Geert Josten Sent: 2014-04-14 12:42 To: 'MarkLogic Developer Discussion' Subject: Re: [MarkLogic Dev General] date and dateTime comparison Would be great though if MarkLogic would allow putting a date index on dateTime based values.. Would save some manual work.. RFE? ;-) Cheers, Geert Van: Geert Josten [mailto:[email protected]] Verzonden: maandag 14 april 2014 12:40 Aan: 'MarkLogic Developer Discussion' Onderwerp: RE: [MarkLogic Dev General] date and dateTime comparison Hi Jakob, Exactly the same approach I took when I had dateTime attributes, while we wanted to allow searching on date facets.. Cheers, Geert Van:[email protected]<mailto:[email protected]> [mailto:[email protected]] Namens Jakob Fix Verzonden: zaterdag 12 april 2014 16:38 Aan: MarkLogic Developer Discussion Onderwerp: Re: [MarkLogic Dev General] date and dateTime comparison Thanks David, I ended up separating time and date values into an attribute and element, respectively, as you suggested, with an element-range-index on the element's value. As I wanted to get this as JSON in the end, this is what I'm using right now (0.002 secs :-)): xdmp:to-json( for $date in cts:element-values(xs:QName("normalized-date"), ()) order by $date descending return map:new(( map:entry("date", $date), map:entry("count", cts:frequency($date)) )) ) cheers, Jakob. On Thu, Apr 10, 2014 at 11:26 PM, David Ennis <[email protected]<mailto:[email protected]>> wrote: I would personally use another element or even split the date and time into two fields. Then you would use a range index on the date field of the type date. Of course, you can also just store the date part as an attribute of the current element and work off of an element-attribute-index and wrk on the same solutions. to get your results (pseudocode) for $res in (for $date in cts:element-values(xs:QName("yourdatefieldhere"), (set the frequency order options here) return <res><date>{$date}</date><count>{cts:frequencies($date)}</count></date>) order by $res/count return $res the result from element-values is from an index and is already a list of distinct-values. Regards, David On 10 April 2014 22:50, Jakob Fix <[email protected]<mailto:[email protected]>> wrote: Hello, How would one go about this one: I'm storing dateTime values for each document. I want to retrieve, efficiently, all unique dates (irrespective of the time part) and the number of items with that date. The naive implementation (because it takes about 1.5 seconds for not much data): let $c := collection("item") return for $d in distinct-values($c ! xs:date(xs:dateTime(.//normalized-dateTime/text()))) order by $d descending return concat($d, " - ", count($c//item[xs:date(xs:dateTime(.//normalized-dateTime)) = $d])) The profiler tells me that it's spending about 85% of the time in the predicate in the last line, so an index would probably speed up the lookups. I created an element range index for the normalized-dateTime element, of type dateTime. What I was hoping to be a bit less naive, turns out to be not feasible: for $d in distinct-values(collection("item")/item ! xs:date(xs:dateTime(./normalized-dateTime/text()))) order by $d descending return concat($d, " - ", count( cts:search(/item, cts:and-query(( cts:collection-query("item") , cts:element-range-query(xs:QName("normalized-dateTime"), "=", $d) )) ) ) ) Now it complains that there is no element range index of type date for the normalized-dateTime element, which is correct... Would the recommendation be to add another element, normalized-date, that contained only the date part and work with that, or is there possibly another, even simpler solution? cheers, Jakob. _______________________________________________ General mailing list [email protected]<mailto:[email protected]> http://developer.marklogic.com/mailman/listinfo/general _______________________________________________ General mailing list [email protected]<mailto:[email protected]> http://developer.marklogic.com/mailman/listinfo/general
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