Embeds postgres, and fetches the data in real time.
select
aws.name aws_user_name,
slack.id as slack_user_id,
slack.display_name as slack_name
from
aws_iam_user as aws,
slack_user as slack
where
aws.name = slack.email;
+--------------------------+---------------+------------+
| aws_user_name | slack_user_id | slack_name |
+--------------------------+---------------+------------+
| [email protected] | U2EMB8HLP | dwight |
| [email protected] | U02HE4Z7E | jim |
+--------------------------+---------------+------------+