Blogmarks tagged orm in 2010
Filters: Type: blogmark × Year: 2010 × orm × Sorted by date
Easier custom Model Manager Chaining. A neat solution to the problem of wanting to write a custom QuerySet method (.published() for example) which is also available on that model’s objects manager, without having to write much boilerplate. # 20th July 2010, 6:21 pm
On Django And Migrations. South author Andrew Godwin on the plans for migrations in Django. His excellent South migration library will be split in to two parts—one handling database abstraction, dependency resolution and history tracking and the other providing autodetection and the South user interface. The former will go in to Django proper, encouraging other migration libraries to share the same core abstractions. # 2nd June 2010, 4:27 pm
Appending the request URL to SQL statements in Django. A clever frame-walking monkey-patch which pulls the most recent HttpRequest object out of the Python stack and adds the current request.path to each SQL query as an SQL comment, so you can see it in debugging tools such as slow query logs and the PostgreSQL “select * from pg_stat_activity” query. # 2nd June 2010, 9:09 am
Cache Machine: Automatic caching for your Django models. This is the third new ORM caching layer for Django I’ve seen in the past month! Cache Machine was developed for zamboni, the port of addons.mozilla.org to Django. Caching is enabled using a model mixin class (to hook up some post_delete hooks) and a custom caching manager. Invalidation works by maintaining a “flush list” of dependent cache entries for each object—this is currently stored in memcached and hence has potential race conditions, but a comment in the source code suggests that this could be solved by moving to redis. # 11th March 2010, 7:35 pm
Announcing django-cachebot. The ORM caching space around Django is heating up. django-cachebot is used in production at mingle.com and takes a more low level approach to cache invalidation than Johnny Cache, enabling you to specifically mark the querysets you wish to cache and providing some advanced options for cache invalidation. Unfortunately it currently relies on a patch to Django core to enable its own manager. # 6th March 2010, 12:48 pm
Johnny Cache. Clever twist on ORM-level caching for Django. Johnny Cache (great name) monkey-patches Django’s QuerySet classes and caches the result of every single SELECT query in memcached with an infinite expiry time. The cache key includes a “generation” ID for each dependent database table, and the generation is changed every single time a table is updated. For apps with infrequent writes, this strategy should work really well—but if a popular table is being updated constantly the cache will be all but useless. Impressively, the system is transaction-aware—cache entries created during a transaction are held in local memory and only pushed to memcached should the transaction complete successfully. # 28th February 2010, 10:55 pm