Issue dumping schema using readonly user

Here’s the situation:

    % psql --version   psql (PostgreSQL) 9.3.5   % postgres --version   postgres (PostgreSQL) 9.3.5   % psql mydatabase   create table mytable_is_readonly (id uuid primary key, text text not null);   create table mytable_is_not_readonly (id uuid primary key, text text not null);   create user readonly with password 'readonly';   grant select on mytable_is_readonly to readonly;
   % psql mydatabase readonly   \d mytable_is_readonly                            Table "public.mytable_is_readonly"    Column │  Type   │                            Modifiers   ────────┼─────────┼──────────────────────────────────────────────────────────────────    id     │ integer │ not null default nextval('mytable_is_readonly_id_seq'::regclass)    text   │ text    │ not null   Indexes:       "mytable_is_readonly_pkey" PRIMARY KEY, btree (id)
   \d mytable_is_not_readonly                            Table "public.mytable_is_not_readonly"    Column │  Type   │                              Modifiers   ────────┼─────────┼──────────────────────────────────────────────────────────────────────    id     │ integer │ not null default nextval('mytable_is_not_readonly_id_seq'::regclass)    text   │ text    │ not null   Indexes:       "mytable_is_not_readonly_pkey" PRIMARY KEY, btree (id)
   % pg_dump -U readonly mydatabase --schema-only --table=mytable_is_readonly   ... this outputs and works
   % pg_dump -U readonly mydatabase --schema-only --table=mytable_is_not_readonly   pg_dump: [archiver (db)] query failed: ERROR:  permission denied for relation mytable_is_not_readonly   pg_dump: [archiver (db)] query was: LOCK TABLE public.mytable_is_not_readonly IN ACCESS SHARE MODE

Is this a bug? Or defined behavior that is expected? My use case is that I have some tables that I don’t want to allow the readonly account to access data in but want to allow it to see the schema of that table. My guess was that since it could see the schema interactively in psql, that it should be allowed to pg_dump the table with schema only no problem.

Thanks for the help!

- Dan