Example of utilizing flattened data for this gg discussion https://groups.google.com/forum/#!topic/firebase-angular/UEI1WugYPUI

portfolios.js

// list my portfolios

var userId = 'kato';
var ref = new Firebase('.../portfolios/'+userId);
var portfolioList = $firebase(ref).$asArray();

// add a new column

$scope.addColumn = function(portfolio, newColumnName) {
   portfolio.columns[newColumnName] = true;
   portfolioList.$save(portfolio);
};

// remove a column

$scope.removeColumn = function(portfolio, oldColumnName) {
   delete portfolio.columns[oldColumnName];
   portfolioList.$save(portfolio);
};

// fetch data for a portfolio

$scope.getPortfolioData = function(portfolio) {
  var ref = new Firebase('.../portfolio_data').child(portfolio.$id);
  $scope.data = $firebase(ref).$asObject();
};