ionic framework use cordova sqlite slowly

I use ionic framework with cordova sqlite plugin, I use chrome to test, It work, but I have a problem. The sqlite to select so slow, I always to wait it. I have no idea, thanks your help.

First this is my controller

...
.controller('TestDetailCtrl', function($scope, $sce, $stateParams, SQLService) {
  var content = '';
  SQLService.get_one($stateParams.testId).then(function(res) {
    content = res[0];
    $scope.test = content;
    $scope.html_content = $sce.trustAsHtml(content.content);
  });
})
...

This is my factory

...
  function get_one(content_id) {
    return promisedQuery("SELECT * FROM pixnet WHERE content_id = '" + content_id + "'", defaultResultHandler, defaultErrorHandler);
  }

  function defaultResultHandler(deferred) {
    return function(tx, results) {
      var len = results.rows.length;
      var output_results = [];

      if (len > 0) {
        for (var i=0; i<len; i++){
          var t = {
            'id': results.rows.item(i).id,
            'content_id': results.rows.item(i).content_id,
            'title': results.rows.item(i).title,
            'url': results.rows.item(i).url,
            'content': results.rows.item(i).content
          };
          output_results.push(t);
        }
      }

      deferred.resolve(output_results);
    }
  }

  function defaultErrorHandler(deferred) {
    return function(tx, results) {
      console.log('Error results', results);
      var len = 0;
      var output_results = '';
      deferred.resolve(output_results);
    }
  }

  return {
    setup: function() {
      return createDB();
    },
    ...
    get_one: function (content_id) {
      return get_one(content_id);
    }
  }
...