database 1.2G, pg_dump 73M?!

I have a postgres server for which du reports
1188072    /var/lib/postgresql/8.2/main
on  Linux system.
The server has only one real database, which is for bacula.  When I dump
the database, it's 73Mg.

This is immediately after I did a full vacuum and restarted the server.

Also,
bacula=> SELECT relname, relpages FROM pg_class ORDER BY relpages DESC
limit 15;
             relname             | relpages
---------------------------------+----------
 file_jpfid_idx                  |    27122
 file_pathid_idx                 |    17969
 file_jobid_idx                  |    17948
 file_pkey                       |    14580
 file_fp_idx                     |    12714
 file                            |    11558
 file_filenameid_idx             |     9806
 filename                        |     3958
 filename_name_idx               |     2510
 filename_pkey                   |     1367
 path                            |      966
 path_name_idx                   |      950
 path_pkey                       |      151
 pg_attribute_relid_attnam_index |       46
 pg_proc                         |       45

It seems very strange to me that there is such a difference in size
between the dump and the database: the data store is almost 15 time
larger than the dump.

Is this to be expected (e.g., from the indices taking up disk space)?
Is there anything I can do to reclaim some disk space?

Thanks.
Ross