[MarkLogic Dev General] using a collation for sorting volume numbers

James A. Robinson jim.robinson at stanford.edu
Mon Jun 4 15:52:20 PDT 2007


> I have a set of documents that have volume and issue numbers  
> represented as strings (e.g. 1, 10, 2, 23).  If I use the following  
> collation, I get a nice numeric sort without having to pad or  
> otherwise normalize the data, but performance suffers.  Is there an  
> index I can add that would speed up the kind of sorting that this  
> collation needs to do?
> 
> for $i in cts:search(doc()//article-title,"water")
> order by $i/root()//volume collation "http://marklogic.com/collation/ 
> en/MO"
> return
> $i/root()//volume

I was curious re the use of collataion -- are your values actually numeric
values? If so  I'd have assumed a way to do this sort of sorting would
be something like

  for $d in $set
  order by xs:decimal($d/volume), xs:decimal($d/issue)
  return ...

and so forth.  Is this naive?  I understand why it wouldn't work for
things like '10a' or something, but for pure numbers, even if they are
padded with leading zeros, I had assumed a cast would work.

Jim

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James A. Robinson                       jim.robinson at stanford.edu
Stanford University HighWire Press      http://highwire.stanford.edu/
+1 650 7237294 (Work)                   +1 650 7259335 (Fax)


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