Scenario: you need a database record that can belong to one record or another, but not both. Polymorphism and exclusivity. One approach is to create a polymorphic-style association at the data layer. By doing so, you’ll get data integrity built in, rather than trusting it will be enforced by each tenant at the application layer.

RC files, thought to stand for “run command” files, are read by a program during startup. The file that configures the PostgreSQL REPL psql is called .psqlrc. In this post I’ll share my personal psql configuration.

Have you ever tried to read the documentation for a Postgres command? Although many consider Postgres’ docs best-in-class, they include conventions that might challenge newbies. In this post, I’ll paraphrase Postgres’ conventions page to help us understand what the documentation for a command is saying.

We introduced some breaking database changes to our Phoenix port of Today I Learned on Friday; today I deployed them to staging. Resetting an Ecto Heroku database, with new seed data, turned out to be a little tricky, and I wanted to document what I learned.