partitoning-with-xquery.xqy

(: better approach as allows you to use xdmp:estimate :)
declare function local:partition-range($list-size, $nr-partitions) {
let $m    := if ($nr-partitions > $list-size) 
             then $list-size 
             else $nr-partitions,
    $step := ceiling( $list-size div $m )
return 
  for $i in (1 to $m)    
    let $s := xs:integer( 1 + ( ( $i - 1 ) * $step ) )
    let $f := xs:integer( $s + $step - 1 )
    return <partition start={$s} end="{$f}"/> };

local:partition-range( 10, 3 )