Use eager loading to reduce query load on index pages

[uberbrady]

On any page that is a list of 'things' - which then refers to any associated sub-things - we should eager-load the sub-things.

This should substantially reduce query load by basically performing a JOIN for us.

You'd notice this more on a page that had a large list of 'things' where it was referring to bits of the sub-things on the each line.

[kds100]

Had to add eager loading to solve performance issues with a large set of assets. Here is an example of the altered code for getIndex in the AssetsController.

public function getIndex()
{
// Grab all the assets

    // Filter results
    if (Input::get('Pending'))
    {
        $assets = Asset::orderBy('asset_tag', 'ASC')->whereNull('status_id','and')->where('assigned_to','=','0')->where('physical', '=', 1)->get();
    }
    else if (Input::get('RTD'))
    {
        $assets = Asset::orderBy('asset_tag', 'ASC')->where('status_id', '=', 0)->where('assigned_to','=','0')->where('physical', '=', 1)->get();
    }
    else if (Input::get('Undeployable'))
    {
        $assets = Asset::orderBy('asset_tag', 'ASC')->where('status_id', '>', 1)->where('physical', '=', 1)->get();
    }
    else if (Input::get('Deployed'))
    {
        $assets = Asset::orderBy('asset_tag', 'ASC')->where('status_id', '=', 0)->where('assigned_to','>','0')->where('physical', '=', 1)->get();
    }
    else
    {
        // ADDED Eager Loading params for Model, Assigned User, Asset Location - decreases load time significantly
        // Note the addition of AssetsStatus to complete the loading improvement.
        // Debug Mode still has overhead, but much more manageable
        $assets = Asset::with('model','assigneduser','assetloc','assetstatus')->orderBy('asset_tag', 'ASC')->where('physical', '=', 1)->get();
    }

    // Paginate the users
    /**$assets = $assets->paginate(Setting::getSettings()->per_page)
        ->appends(array(
            'Pending' => Input::get('Pending'),
            'RTD' => Input::get('RTD'),
            'Undeployable' => Input::get('Undeployable'),
            'Deployed' => Input::get('Deployed'),
        ));
    **/

    return View::make('backend/hardware/index', compact('assets'));
}