Hi William,

Your query will be evaluated in appr. 100-200 ms if you do some little
rewritings. Here is one variant:

  declare function local:compare($actual, $prev) {
    for $c in $actual/portfolio/asset
    return <asset>
      { $c/* },
      <prev-category>{
        $prev/portfolio/asset[assetid/text() =
$c/assetid/text()]/category/text()
      }</prev-category>
    </asset>
  };

  declare variable $act external := "2017-07";
  declare variable $prv external := "2016-07";

  (: external resources :)
  local:compare(doc($act || '.xml'), doc($prv || '.xml'))

  (: external resources :)
  local:compare(db:open($db, $act || '.xml'), db:open($db, $prv || '.xml'))

Some notes:

• It is always advisable to directly address text nodes in your query:
assetid → assetid/text(). The reason is that an element node may
contain multiple text nodes, which would need to be concatenated for a
text comparison. The text index in BaseX, however, works on single
text nodes, which means that a path expression will only be rewritten
for index access if it can be derived statically that the target node
will be a single text.

• If you call a function, the body is more likely to be rewritten for
index access if you pass on the whole document instead of child or
descendant nodes: /portfolio → doc(...).

If you open the "Info" panel in the GUI, you can look for the string
"apply text index" in order to ensure that indexes will be utilized.

Hope this helps,
Christian

On Sun, Feb 4, 2018 at 3:03 AM, <wd@creativosdigitales.co> wrote:

Hi,

I'm using BaseX to compare two XML documents with a list of items <asset>
identified by an element <assetid> and with a

Now I need to consolidate them in only one document with the value of the
<category> element in both documents (one of them renamed to
<prev-category>).

Attached are samples of these documents., and the quey I'm using is this:

declare function local:compare( $actual, $prev ){

  for $c in $actual/asset

    return <asset>

        { $c/*}

        <prev-category>

        { $prev/asset[assetid = $c/assetid]/category/text() }

        </prev-category>

    </asset>

};

declare variable $act external := "2017-07";

declare variable $prv external := "2016-07";

return local:compare(/portfolio[projectid=$act],
/portfolio[projectid=$prv]
)

The query takes 42 seconds when run over the files. If I load the files to
a
database and activate the text index, it takes 125 seconds.

This is a very common query in relational databases that takes only ssfew
seconds to run joining two tables or two subqueries.

Is there a way to make it run faster in BaseX?

Thanks for your advice,

William David Velásquez

Creativo de Software

Creativos Digitales S.A.S.

Calle 30A # 83 - 53 Local 1033

Tel: 322 1730 - 311 709 8421

Medellín, Colombia

http://creativosdigitales.co