title: Change integer to bigint key in a table without long exclusive lock
body: <p>Is it possible to inherit a table with column of type <code>int</code> from a table with the same column of type <code>bigint</code> in PostgreSQL 9.1?</p>
  
  <p>Changing the column type to <code>bigint</code> if the first table is not an option.</p>
  
  <p>I have a table with several tens of millions entries that has an ID of int. Right now that ID is slowly approaching to 2^32, and I was thinking if it's a reasonable thing to create a facade table with bigint ID and let the original one inherit the facade. Does it make any sense? </p>