needless query in handler views_handler_filter_term_node_tid

As far as I can tell, what this code in views_handler_filter_term_node_tid does is get all vocabs, then query {vocabulary} again to find the lowest vocab ID, to set this as the default value.

Firstly this is not going to give you the first vocab in the list, as the user may have reordered them and put the vocab with the lowest vid below others.

Second, the query us needless as we already have to hand $vocabularies, which is indexed by vid, and to boot, in the right weight order!

So we just in fact want the first element in $vocabularies.

    $vocabularies = taxonomy_get_vocabularies();
    foreach ($vocabularies as $voc) {
      $options[$voc->vid] = check_plain($voc->name);
    }

    if ($this->options['limit']) {
      // We only do this when the form is displayed so this query doesn't run
      // unnecessarily just when the object is constructed.
      if ($this->options['vid'] == 0) {
        $this->options['vid'] = db_result(db_query('SELECT MIN(vid) FROM {vocabulary} v'));
      }

Patch coming.