Okay thanks

I wrote the following query which returns 59 distinct periods from a 8gb db.. It's quite slow but it works

let $periods := distinct-values(db:open("13F")//data/@periodOfReport)
let $transform :=
<periods>
   {
    for $period in $periods    
    return <period>{$period}</period>
    }
</periods>

return file:write('/var/www/appusec3.jahtoe.com/xml/periods.xml', $transform)


Regards
Alex
tech.jahtoe.com
bafila.jahtoe.com

On Mon, Jul 11, 2016 at 6:21 PM, Christian Grün <christian.gruen@gmail.com> wrote:
> any way to retrieve the index for a specific attribute name?

Nope, sorry. The index itself has no information on the location of
the text and attribute values. You’ll have to use distinct-values:

  distinct-values(//periodOfReport)

If the number of distinct values is smaller than MAXCATS [1], the path
index will be utilized to speed up your query [2]. You can set MAXCATS
to a much larger value, but this might slow down the time required for
opening a database.

Hope this helps
Christian

[1] http://docs.basex.org/wiki/Options#MAXCATS
[2] http://docs.basex.org/wiki/Indexes#Path_Index