Constant file growth.

Hello

I have noticed that my postgresql database sees a constant growth to some of
the system files:

184M 17112
Database=# select relname from pg_class where relfilenode = 17112;
relname
---------------------------------
pg_attribute_relid_attnam_index
(1 row)

77M 17115
Database=# select relname from pg_class where relfilenode = 17115;
relname
---------------------------------
pg_attribute_relid_attnum_index
(1 row)

44M 17121
Database=# select relname from pg_class where relfilenode = 17121;
relname
------------------------
pg_class_relname_index
(1 row)

These files represent 305M out of the 454M of my database. Any hints on why
it is so and how I can fix it would be greatly appreciated. Dropping and
reloading is next to useless. I am using 7.1.3 under FreeBSD 4.3.

Alex