Thanks for your quick answer. Query execution improves its timing a lot.

One more question, in a similar query but with attributes, it looks like the index doesn´t get applied (more similar to our real situation):

XML is similar to:

<businessEvent>
<inputs>
    <input name="data">
      <input element="229388252" name="id" type="String"/>
      <input element="2751 XTE" name="matriculation" type="String"/>
      <input element="XTETVTTJKC" name="clientId" type="String"/>
      <input name="driver">
        <input element="driver name" name="name" type="String"/>
        <input element="driver surname" name="surname" type="String"/>
        <input element="21973887X" name="nif" type="String"/>
        <input element="line 1" name="line1" type="String"/>
        <input element="Line 2" name="line2" type="String"/>
        <input element="City name" name="city" type="String"/>
        <input element="28197" name="cp" type="String"/>
        <input element="Region7" name="region" type="String"/>
        <input element="Country" name="country" type="String"/>
      </input>
      <input name="accident">
        <input name="date">
          <input element="2012" name="year" type="String"/>
          <input element="13" name="month" type="String"/>
          <input element="22" name="day" type="String"/>
          <input element="2" name="hour" type="String"/>
          <input element="53" name="minute" type="String"/>
        </input>
        <input name="address">
          <input element="Avenue 5" name="line1" type="String"/>
          <input element="Line2" name="line2" type="String"/>
          <input element="Madrid" name="city" type="String"/>
          <input element="28224" name="cp" type="String"/>
          <input element="Region3" name="region" type="String"/>
          <input element="Spain" name="country" type="String"/>
        </input>
        <input element="Lorem ipsum dolor …." name="declaration" type="String"/>
      </input>
    </input>
  </inputs>
</businessEvent>


Execution:


Query: <result>{ for $col1 in (db:open('bbdd_1')//businessEvent ), $col2 in (db:open('bbdd2')//businessEvent) for $income in distinct-values($col2//inputs/input[@name='data']/input[@name='accident']/input[@name='address']/input[@name='region']/data(@element)) where $col1//inputs/input[@name='data']/input[@name='id']/data(@element)=$col2//inputs/input[@name='data']/input[@name='id']/data(@element) group by $income return <line><label>{ $income }</label><data>{ count($col2) }</data></line>}</result>
Compiling:
- rewriting where clause to predicate(s)
- pre-evaluating db:open("bbdd_1")
- simplifying descendant-or-self step(s)
- converting descendant::*:businessEvent to child steps
- pre-evaluating db:open("bbdd_2")
- simplifying descendant-or-self step(s)
- simplifying descendant-or-self step(s)
- swapping operands: descendant::*:inputs/*:input[@*:name = "data"]/*:input[@*:name = "id"]/fn:data(@*:element) = $col1/descendant::inputs/input[@name = "data"]/input[@name = "id"]/fn:data(@element)
- simplifying descendant-or-self step(s)
- converting descendant::*:businessEvent[descendant::*:inputs/*:input[@*:name = "data"]/*:input[@*:name = "id"]/fn:data(@*:element) = $col1/descendant::inputs/input[@name = "data"]/input[@name = "id"]/fn:data(@element)] to child steps
- simplifying descendant-or-self step(s)

Result: element result { for $col1 in (document-node { "1361200546116" }, ...)/*:businessEvent for $col2 in (document-node { "1361200600857" }, ...)/*:businessEvent[descendant::*:inputs/*:input[@*:name = "data"]/*:input[@*:name = "id"]/fn:data(@*:element) = $col1/descendant::inputs/input[@name = "data"]/input[@name = "id"]/fn:data(@element)] for $income in fn:distinct-values($col2/descendant::inputs/input[@name = "data"]/input[@name = "accident"]/input[@name = "address"]/input[@name = "region"]/fn:data(@element)) group by $income := $income return element line { element label { $income }, element data { fn:count($col2) } } }

Timing:
 - Parsing:  1.24 ms
 - Compiling:  7.44 ms
 - Evaluating:  36090.05 ms
 - Printing:  0.64 ms
 - Total Time:  36099.37 ms



Is it possible that the index doesn’t get applied?, how could I improve this query?