PostgreSQL & Django - a tasty mix

My talk at PyWaw #26.
http://www.pywaw.org/08-07-2013

Transcript

1. PostgreSQL & Django A tasty mix PyWaw #26, 08.07.2013 Zbigniew Siciarz @zsiciarz http://siciarz.net
2. DjangoCon-inspired • Advanced PostgreSQL in Django by Christophe Pettus http://www.youtube.com/watch?v=C3bZbA4jaAg • Getting past the Django ORM limitations with Postgres by Craig Kerstiens http://www.youtube.com/watch?v=sXmFK_qsvlo
3. Case study • pretty slides are pretty, but show me the code • practical example? • yet another online photo gallery… • …built with Django… • …using PostgreSQL goodies!
4. HStore
5. NoSQL in my SQL?! • HStore is a key value store within Postgres. You can use it similar to how you would use a dictionary within another language […] – Craig Kerstiens, Postgres Guide http://postgresguide.com/sexy/hstore.html • CREATE EXTENSION hstore;
6. This is Hastur, not HStore http://www.goominet.com/lovecraft/
7. django-hstore • pip install django-hstore • exif = hstore.DictionaryField(db_index=True) • photo.exif = {‘FocalLength’: ‘11’} • South sometimes gets confused • custom database backend • who maintains the code?
8. Where do we go from here?
9. djorm-ext-hstore • fork of django-hstore • actively maintained and improved • plays nice with South • no need for custom database backend • Yay!
10. Storing EXIF data in HStore
11. Storing EXIF data in HStore
12. Storing EXIF data in HStore
13. array
14. [] • multiple values of the same type in one column • built-in; no extension needed • variable length arrays • maps well to a Python list
15. djorm-ext-pgarray • same maintainer as djorm-ext-hstore and other ORM extensions • provides model field and form field • pip install djorm-ext-pgarray • or… • https://github.com/ntucker/djorm-ext-pgarray (better tag string parsing in ArrayFormField)
16. Tagging images
17. @> • @> means „contains” • zs=> select array[1,2,3] @> array[2,1]; ?column? ---------- t (1 row) • use djorm-ext-expressions for Pythonic syntax
18. Tags in forms
19. Popular tags
20. Putting it all together • django-pgallery https://github.com/zsiciarz/django-pgallery • proof-of-concept code • TODO: tests, docs, better templates… • pull requests are welcome :-)
21. Questions?
22. Thank you!