The day PostgreSQL saved my butt from Django and TSearch2

LingQ recently integrated TSearch2 a full text engine for PostgreSQL. TSearch2 improves the search accuracy and speed it up. LingQ is built with Django, and we ran into a major issue regarding Django and TSearch2 integration: the test command which runs unit tests was broken.

When unit tests are run; Django creates an empty database. Thus the operations performed during the tests don't overwrite the data on the working database. TSearch2 needs to be installed on the newly created database; it needs to install a new SQL type: tsvector and some other stuffs. Without it the table creation failed.

Unfortunately Django does not provide any means of running SQL code immediately after the database creation.

The solution: Template Databases

PostgresSQL provide a mechanism called Template Databases. The database creation works by copying an existing database: template1. Installing TSearch2 on the database template1 solves the problem:

sudo -u postgres psql template1 < /path/to/tsearch2.sql

Everything runs smoothly now. Thanks to PostgreSQL we did not have to throw away all our unit tests to use TSearch2!

If my writing sparked any ideas, questions, or insights, I would love to hear from you.
Email me at henry@precheur.org I read and respond to each email.