Help! "alter table add column" hangs - Mailing list pgsql-novice

Sorry, I had meant to write:

  The command

    ALTER TABLE some_table ADD COLUMN some_column CHAR(6) UNIQUE;
                ^^^^^^^^^^
  hangs indefinitely (hours!), even though the table is relatively small
  (about 2500 records).

  What gives?

  Thanks,

  kj