Postgres has dozens of connection variables it will take, a couple of my favorite ones are statement_timeout and application_name.
Ecto takes a parameters connection option, which is a keyword list of connection parameters.
# dev.exs
...
# Configure your database
config :myapp, Myapp.Repo,
adapter: Ecto.Adapters.Postgres,
database: "myapp_dev",
socket_dir: "/var/run/postgresql",
parameters: [application_name: "My App Development", statement_timeout: "5000"],
pool_size: 10
Example of statement_timeout being respected in Ecto:
Ecto.Adapters.SQL.query!(Myapp.Repo, "select pg_sleep(86400)")
** (Postgrex.Error) ERROR 57014 (query_canceled): canceling statement due to statement timeout
(ecto) lib/ecto/adapters/sql.ex:200: Ecto.Adapters.SQL.query!/5
Client Connection Variables references:
https://www.postgresql.org/docs/current/static/runtime-config-client.html