DEV Community: Lang Sharpe

Introduction to Timezones in Rails

Lang Sharpe — Wed, 17 Feb 2021 23:21:02 +0000

One day I'll do the perfect presentation about timezones.

For now, I did a talk at RoRoSyd in December 2020. This is called "Introduction to Timezones" and discusses what a time zone is, how Rails handles them and how to use them in a way that makes sense.

Creating indexes in PostgreSQL isn't always idempotent

Lang Sharpe — Mon, 14 Oct 2019 08:29:30 +0000

Usually, when you call CREATE INDEX in Postgres, you expect the index to be created, or an error to be raised. However, if you are doing each of these:-

Creating a UNIQUE index
The data is not unique
Creating the index CONCURRENTLY

An index will be created, but be INVALID. From the documentation:-

If a problem arises while scanning the table, such as a deadlock or a uniqueness violation in a unique index, the CREATE INDEX command will fail but leave behind an “invalid” index.

Source

Rails Seed tasks

Lang Sharpe — Wed, 09 Oct 2019 08:02:36 +0000

A few tasks will load your seed data

rails db:setup
rails db:reset

This surprised me. I had thought they were only loaded when db:seed is run specifically.

Using netcat as a test statsd server

Lang Sharpe — Thu, 03 Oct 2019 08:02:20 +0000

Netcat will listen on a port and write what it receives to stdout.

nc -u -l -p 8125
# -u UDP
# -l Listen
# -p Port

It only works for a single line/connection. (Other versions have an option to keep listening. However, I wasn’t able to find one that ran on MacOS).