With ML6 I think you could create a single, useful path range index on both 
elements. There is a table of permitted XPath syntax at 
http://docs.marklogic.com/guide/admin/range_index#id_54948 and syntax like 
/a/(b|c) is supported.

So you're answer might be "this will be slow now, but we have a plan to make it 
faster when we upgrade".

-- Mike

On 2 Aug 2013, at 10:40 , Ron Hitchens <[email protected]> wrote:

> 
>   This one is on 5.x.  I plan to move them to 6.x for
> the next phase (where everything goes to a consistent model),
> but it's not possible now.
> 
>   If you know a way on 6.x I'd love to see it.  We can't
> use path range indexes, but how would that work?  Something
> like this?:
> 
> order by xs:date ($result/(old/path/date|new/path/m:sort-date))
> 
> On Aug 2, 2013, at 6:13 PM, Michael Blakeley <[email protected]> wrote:
> 
>> Which release?
>> 
>> So you're using an element-range index? What about using a path-range index?
>> 
>> -- Mike
>> 
>> On 2 Aug 2013, at 09:26 , Ron Hitchens <[email protected]> wrote:
>> 
>>> 
>>> I have a sorting problem that I can't find a good solution
>>> for.  I'm working on a project where a lot of content exists in
>>> one form which was not designed for efficient searching or sorting.
>>> In fact, MarkLogic is not used at all for search at the moment,
>>> that's what I'm adding.
>>> 
>>> This existing format has multiple versions of the content
>>> in each document, with an element range index on an xs:date field.
>>> I can do efficient sorts on this content alone using the ranged
>>> date field in an "order by" clause.
>>> 
>>> Here's the complication: a new type of content is being added
>>> in a newer, more MarkLogic-friendly schema.  These documents all
>>> have a common metadata section with a ranged date field.  Different
>>> name and namespace, but serving the same purpose.
>>> 
>>> My problem is that I need to do searches across both types of
>>> content and sort them together.  Searching one kind or the other
>>> and sorting by their respective date fields works great for massive
>>> result sets.  But doing them together blows the expanded tree cache
>>> if the result set is large.
>>> 
>>> Because of the odd layout of the old content, my searchable
>>> expression is rather funky and looks something like this:
>>> 
>>> cts:search 
>>> (fn:doc()/(/container/group[@state="live]/doc[fn:not(@foo)]|x:new1|x:new2), 
>>> $q, "unfiltered")
>>> 
>>> Note that the first one returns a sub-element of the document,
>>> which is actually a fragment root.  The other two on the end return
>>> root elements.
>>> 
>>> A FLWOR like this doesn't work:
>>> 
>>> for $result in cts:search ( . . .)
>>> order by xs:date (($result/old/path/date, $result/new/path/m:sort-date)[1])
>>> return $result
>>> 
>>> It runs but ok and will do the right thing if the result
>>> set is reasonably small (a few thousand) will blow the cache
>>> if there are too many results.  Trying to ignore one of the
>>> dates also blows he cache:
>>> 
>>> for $result in cts:search ( . . .)
>>> order by xs:date ($result/old/path/date)
>>> return $result
>>> 
>>> But removing the last two components of the XPath (|x:new1|x:new2)
>>> will then run fast.  I'm not sure why this prevents the range index
>>> from kicking in, probably because of the complexity of the XPath.
>>> 
>>> Sorting combined results by relevance in either direction is fast.
>>> 
>>> Does anyone have a voodoo trick to enable fast sorting using values
>>> from two different range indexes?  I don't need to look into the documents
>>> the get the sort keys, it seems like it shouldn't have to consume expanded
>>> tree cache space for this.
>>> 
>>> ---
>>> Ron Hitchens {mailto:[email protected]}   Ronsoft Technologies
>>>   +44 7879 358 212 (voice)          http://www.ronsoft.com
>>>   +1 707 924 3878 (fax)              Bit Twiddling At Its Finest
>>> "No amount of belief establishes any fact." -Unknown
>>> 
>>> 
>>> 
>>> 
>>> _______________________________________________
>>> General mailing list
>>> [email protected]
>>> http://developer.marklogic.com/mailman/listinfo/general
>>> 
>> 
>> _______________________________________________
>> General mailing list
>> [email protected]
>> http://developer.marklogic.com/mailman/listinfo/general
> 
> _______________________________________________
> General mailing list
> [email protected]
> http://developer.marklogic.com/mailman/listinfo/general
> 

_______________________________________________
General mailing list
[email protected]
http://developer.marklogic.com/mailman/listinfo/general

Reply via email to