start-client-server.md

Running the server

If you want to run a postgres server, just do this from the root of the repository:

nix run .#start-server 15

Replace the 15 with a 16, and you'll be using a different version. Optionally you can specify a second argument for the port.

You likely have a running postgres, so to not cause a conflict, this uses port 5435 by default.

Actually, you don't even need the repository. You can do this from arbitrary directories, if the left-hand side of the hash character (. in this case) is a valid "flake reference":

# from any arbitrary directory
nix run github:supabase/postgres#start-server 15

Arbitrary versions at arbitrary git revisions

Let's say you want to use a PostgreSQL build from a specific version of the repository. You can change the syntax of the above to use any version of the repository, at any time, by adding the commit hash after the repository name:

# use postgresql 15 build at commit <some commit hash>
nix run github:supabase/postgres/<some commit hash>#start-server 15

Running the client

All of the same rules apply, but try using start-client on the right-hand side of the hash character, instead. For example:

nix run github:supabase/postgres#start-server 15 &
sleep 5
nix run github:supabase/postgres#start-client 16

Running a server replica

To start a replica you can use the start-postgres-replica command.

• first argument: the master version
• second argument: the master port
• third argument: the replica server port

First start a server and a couple of replicas:

$ start-postgres-server 15 5435

$ start-postgres-replica 15 5439

$ start-postgres-replica 15 5440

Now check the master server:

$ start-postgres-client 15 5435

SELECT client_addr, state
FROM pg_stat_replication;
 client_addr |   state
-------------+-----------
 ::1         | streaming
 ::1         | streaming
(2 rows)

create table items as select x::int from generate_series(1,100) x;

And a replica:

$ start-postgres-client 15 5439

select count(*) from items;
 count
-------
   100
(1 row)