Django ORM performance patch
I made a patch for Django to add QuerySet.fields(*fields, **related_fields) and make possible to load only some from master and related models fields. It allows to tune various object list queries when we need only limited subset of all fields, improve general performance and decrease database load. As side effect of this patch support of selecting fields from related models in QuerySet.values() is implemented too. It was changed signature of this method from values(*fields) to values(*fields, **related_fields) but the change is backward compatible.
WebAlchemy vs StaticGenerator
When two months ago I published WebAlchemy code, several people asked me how to make it working with nginx or lighttpd. Yesterday new tool similar to WebAlchemy StaticGenerator was published. Now it seems right time to explain how to use WebAlchemy with nginx and other servers that don't have .htaccess files, highlight some important differences between WebAlchemy and StaticGenerator, and say thanks to Django for signal framework that makes it all possible.
Improved Mathematical Captcha
A week ago I published MathCaptchaForm that I use in my blog for preventing spam. Malcolm Tredinnick and then other people noticed that solution don't protect from replay attacks and once solved question can be used by spam bots on different web-sites. So I added protection against replay attacks and implemented it without database usage. It was original requirement to keep MathCaptchaForm as lightweight as possible.
Mathematical Captcha
When spam bots started to post comments in my blog every day I realized that I need some kind of simple anti-spam protection. I didn't saw yet real anti-spam AI and don't like image captchas. I looked for a mathematical captcha where human is asked to solve a simple mathematical calculation like 3+5=?. Unfortunately I didn't found open-source implementation and write own MathCaptchaForm. A week already I don't see spam posts.
Autogenerated ToC
When I reread my last blog post "WebAlchemy accelerates Django in 100 times" I realized that I wrote too many letters. So to make navigation easy I created simple template filter that extracts from a text ids, replaces '_' with spaces and produces hyperlinked Table of Contents.
WebAlchemy accelerates Django in 100 times
With WebAlchemy only pages involved in form processing are served directly by Django, the rest of the pages most of the time are served directly by Apache as static content with static content speed. In other words for Django-powered site it's possible to achieve speed about 2000 request/sec, against about 500 request/sec with memcached and about 20 request/sec for "typical" (10 fast SQL queries) page without caching at all. Actual performance results of course will vary from server/application/configuration.
Django profiler
django-profile.py allows to analyze any django projects, i.e. to find number of SQL queries used on each page and print common SQL-usage report.
Hello world
I launch the second version of my personal site that is usually called now blog. I get many from the world of open-source and I often feel that I have to give something back to community.
© Dima Dogadaylo