I had a problem: too many fetches from the DB.
So, how to reduce load on the database without major changes to the code?
Cache Manager is the answer. I've managed to reduce number of DB hits as much as 80% in some cases (dictionaries, complex relations). It is using standard cache mechanisms. I'm using it with mathopd.
This is a very simple solution, instead of standard Manager, put this in your model definition as:
`objects = CacheManager()`
Then everythere elase in the code instead of all() or get(...) call all_cached() or get_cached().
I've kept original methods intact, to have an dual access, when you really, really must have frest data from the DB, and you can't wait for cache to expire.
This is much easier to work with, then manually getting fetched data from the cache.No change to your existing code 9except model) and voila!
Additionally if you have some data, you would like to store with your serialized object (e.g. related data, dynamic dictionaries), you can do this in the model method '_init_instance_cache').
Drop me an email if you find this useful. :)
A Django image thumbnail filter, adapted from code by [Batiste Bieler](http://batiste.dosimple.ch/blog/2007-05-13-1/).
This updated version drops support for cropping and just rescales. You should use it in your templates like this:
`<img src='{{ MEDIA_URL }}{{ image.get_image_filename|thumbnail:"300w,listingimages" }}' alt="{{ image.title }}" title="{{ image.title }}" />`
This will produce a 300-pixel wide thumbnail of image, with the height scaled appropriately to keep the same image aspect ratio. 'listingimages' is the path under your MEDIA_ROOT that the image lives in - it'll be whatever upload_to is set to in your ImageField.
If instead you wanted an image scaled to a maximum height of 140px, you'd use something like this:
`<img src='{{ MEDIA_URL }}{{ image.get_image_filename|thumbnail:"140h,listingimages" }}' alt="{{ image.title }}" title="{{ image.title }}" />`
Note the number has changed from 300 to 140, and the trailing letter from 'w' to 'h'.
Please leave feedback and bug reports on [my blog, Stereoplex](http://www.stereoplex.com/two-voices/a-django-image-thumbnail-filter). I've only lightly tested this so you'll probably find something!