Timescale

Extends the Ecto DSL for easily working with TimescaleDB. Already using Ecto and Postgres? Great, you're all set to start working with time-series data.

Features

• Easy creation of hypertables in Ecto Migrations
• Leverage TimescaleDB hyperfunctions right inside your Ecto queries
• Configure table compression policies

Adding the TimescaleDB extension

1. Make sure your database has Timescale correctly installed
2. Create a new Ecto migration
3. Call the create_timescaledb_extension/0 and drop_timescaledb_extension/0 in your migration

E.g.

defmodule MyApp.Repo.Migrations.SetupTimescale do
  use Ecto.Migration

  import Timescale.Migration

  def up do
    create_timescaledb_extension()
  end

  def down do
    drop_timescaledb_extension()
  end
end

Using the Library

Here is an intermediate example querying a timescale reading using Timescale hyperfunctions with timescale's Ecto extensions.

For a more comprehensive example you can check out our guide in the docs here.

import Timescale.Hyperfunctions

Repo.all(
  from(h in "heartbeats",
    where: h.user_id == ^alex_id,
    group_by: selected_as(:minute),
    select: %{
      minute: selected_as(time_bucket(h.timestamp, "1 minute"), :minute),
      bpm: count(h)
    },
    limit: 5
  )
)

Installation

If available in Hex, the package can be installed by adding timescale to your list of dependencies in mix.exs:

def deps do
  [
    {:timescale, "~> 0.1.0"}
  ]
end

Installing Postgres / TimescaleDB on MacOS

There are many ways to install PostgreSQL locally, including Postgres.app, Docker, and building locally. Below is how to install through Homebrew

First, install Postgres

$ brew install postgresql
$ sudo chown $(whoami) /usr/local/var/postgres
$ initdb /usrl/local/var/postgres
$ createuser -s postgres
$ createdb

Make Postgres a service that is started automatically

$ brew services start postgresql

Then install TimescaleDB. For more information about installing TimescaleDB on MacOS, see the official documentation.

$ brew tap timescale/tap
$ brew install timescaledb

# Add the following to `/opt/homebrew/var/postgres/postgresql.conf`
shared_preload_libraries = 'timescaledb'