database names are all numbers now

after i ran vacuum analyze, i see that all my database directories with
respect to their database names have changed to all numbers:

# ls -l /var/pgsql/data
total 17
-rw------- 1 pgsql wheel 4 Dec 30 15:45 PG_VERSION
drwx------ 6 pgsql wheel 512 Jan 8 05:28 base
drwx------ 2 pgsql wheel 512 Jan 3 14:21 global
-rw------- 1 pgsql wheel 7399 Dec 30 15:45 pg_hba.conf
-rw------- 1 pgsql wheel 1118 Dec 30 15:45 pg_ident.conf
drwx------ 2 pgsql wheel 512 Jan 8 16:45 pg_xlog
-rw------- 1 pgsql wheel 595 Jan 8 04:14 postgresql.conf
-rw------- 1 pgsql wheel 93 Jan 8 10:22 postmaster.opts
-rw------- 1 pgsql wheel 22 Jan 8 10:22 postmaster.pid
# ls -l /var/pgsql/data/base
total 8
drwx------ 2 pgsql wheel 1536 Dec 30 16:02 1
drwx------ 2 pgsql wheel 1536 Dec 30 15:45 18719
drwx------ 2 pgsql wheel 2048 Jan 8 16:31 397915
drwx------ 2 pgsql wheel 1536 Jan 8 05:28 9829118

is this normal?