text: -- migrate:up
  CREATE TYPE Command AS ENUM ('RefreshTelemetry');
  CREATE TYPE CommandState AS ENUM ('Created', 'Completed', 'Error');
  
  create table commands
  (
      username           varchar(255) NOT NULL,
      recipient_username varchar(255),
      request            text,
      request_timestamp  TIMESTAMP    NOT NULL,
      response           text,
      response_timestamp TIMESTAMP,
      correlation_id     varchar(255),
      type               Command      NOT NULL,
      state              CommandState NOT NULL
  );
  -- migrate:down
  DROP TABLE commands;
  