Error returned when Squirrelix cannot connect to Postgres for inference.
Covers TCP failures (refused, unreachable, closed) and authorization / catalog
problems. Connection timeouts use Squirrelix.Error.PostgresConnectionTimeout.
Summary
Types
@type reason() ::
:refused
| :unreachable
| :closed
| :nxdomain
| :invalid_authorization
| :invalid_password
| :invalid_catalog
| :unknown