I think there are two types of web applications; one is for admin- site, and the other is for front-site. For admin-site, CPU-usage would be relatively not so critical, and rich man's programming (fat models in web2py) could be allowed. Front-site, on the other hand, needs optimization as far as possible, which put developers some works.
Kenji On 12月2日, 午後1:43, Bruno Rocha <[email protected]> wrote: > Actually you dont need even an ajax callback. > > Take this example: > > ## models/script.py ## > > db.define_table("mytable", Field("picture", "upload")) > print "models executed!" > > ## controllers/default.py ## > > def index(): > pictures = db(db.mytable).select() > return dict(pictures=pictures) > > def download(): > return response.download(request, db) > > ## views/default/index.html ## > > {{for picture in pictures:}} > <img src="{{=URL('default', 'download', args=picture.picture)}}"> > {{pass}} > > Let's say the table has 200 records and I want to show 200 thumbnails in > the page. > > Q: How many times you will see "models executed!" in terminal? and how many > times the table will be defined? the Auth, Crud, Service etc will be > instantiated? > > A: 201 times. 1 for the first request and 200 for each image which calls > the 'download' function. > > Now imagine a system which huge model files, too many tables and calling > long running funtions. > > my tips: > > 1. Avoid models, use modules and import what you need in controller. > > 2. Avoid the download function, put uploadfolder='static' and build > URL('static') when need an image. Or put your download function in a > separate application which have access to the file system and database. > -- > > Bruno Rocha > [http://rochacbruno.com.br]
