title: Why does Postgres tell me that cross database references are not available when both tables are on the same database?
body: <p>Here's the SQL:</p>
  
  <pre><code>CREATE TABLESPACE fnord1 location '/tmp/fnord1';
  CREATE TABLESPACE fnord2 location '/tmp/fnord2';
  
  CREATE SCHEMA IF NOT EXISTS fnord;
  
  DROP TABLE IF EXISTS fnord.shea;
  DROP TABLE IF EXISTS fnord.wilson;
  
  CREATE TABLE fnord.shea (
      id  text not null,
  
      CONSTRAINT fnord_shea_id PRIMARY KEY (id) USING INDEX TABLESPACE fnord2
  ) TABLESPACE fnord1;
  
  CREATE TABLE fnord.wilson (
      thing       text not null,
      shea_id     bigserial not null,
  
      CONSTRAINT fnord_wilson_id PRIMARY KEY (thing, shea_id) USING INDEX TABLESPACE fnord2,
      CONSTRAINT fnord_wilson_shea_fkey FOREIGN KEY (shea_id) REFERENCES fnord.shea.id
  ) TABLESPACE fnord1;
  </code></pre>
  
  <p>This fails because of the foreign key statement, with </p>
  
  <blockquote>
    <p>ERROR:  cross-database references are not implemented: "fnord.shea.id"</p>
  </blockquote>
  
  <p>But... these are in the same database, are they not? If not, what's the right way to get them in the same database?</p>