Question

I often manually pull in production data into my test database so I can test new code on realistic data, as well as test upgrade scenarios or repro data specific bugs. To do this, I’ve setup a VIEW for each production table in my test database. These views look something like this:

CREATE VIEW ProdLink.Users AS
   select * from dblink(
      'hostaddr=123.123.123.123 dbname=ProductionDB user=ROUser password=secret',
      'select * from users') as t1(userid uuid, email varchar(50), alias varchar(50), fullname varchar(50), password varchar(100));

Now, on my production database I can run:

SELECT * FROM ProdLink.Users;

And see all users on my production database. I can then do things like:

INSERT INTO Users SELECT * FROM ProdLink.Users L WHERE NOT EXISTS (select 1 from Users where Users.UserId = L.UserId);

Allowing me to pull in every user from production that doesn’t already exist in test.

I have about 30 of these views to proxy the production data, however I find it somewhat hacky to have to hardcode in the production database connection info into each view.

My Question: Is there a good way to avoid hardcoding, or at least duplicating this connection info on each view? Can I use database level variables, environment variables, or anything else instead?

Answer 1

To avoid duplication you can store the connection strings in a table:

CREATE VIEW ProdLink.Users AS
    select * from dblink(
        (select conn_string from conn_string where conn = 'that_one'),
        'select * from users'
    ) as t1 (
        userid uuid, 
        email varchar(50), 
        alias varchar(50), 
        fullname varchar(50), 
        password varchar(100)
    );