Too many postgres instances

Hi,

Can anyone explain to me why my system is spawn so many postgress instances?
System: FreeBSD 7.2 Stable I386
RAM: < 1GB

Here is the output of the top command:
Mem: 457M Active, 92M Inact, 150M Wired, 23M Cache, 85M Buf, 18M Free
Swap: 999M Total, 150M Used, 849M Free, 14% Inuse

Here is a list of the postgres instances running in my system:
pgsql   70502  0.0  0.5 10364  3800  ??  Ss    2:24AM   0:28.85
postgres: stats collector process    (postgres)
pgsql   70797  0.0  0.4 49724  2892  ??  Is    2:28AM   0:00.24
postgres: liferay lportal 127.0.0.1(54110)  (postgres)
pgsql   70798  0.0  0.7 49724  5060  ??  Is    2:28AM   0:00.43
postgres: liferay lportal 127.0.0.1(52754)  (postgres)
pgsql   70799  0.0  0.0 49724     0  ??  IWs  -         0:00.00
postgres: liferay lportal 127.0.0.1(49593)  (postgres)
pgsql   70800  0.0  0.0 49724     0  ??  IWs  -         0:00.00
postgres: liferay lportal 127.0.0.1(55760)  (postgres)
pgsql   70801  0.0  0.6 49724  5016  ??  Is    2:28AM   0:00.56
postgres: liferay lportal 127.0.0.1(56710)  (postgres)
pgsql   70802  0.0  0.0 49724     0  ??  IWs  -         0:00.00
postgres: liferay lportal 127.0.0.1(65367)  (postgres)
pgsql   70803  0.0  0.6 49724  4508  ??  Is    2:28AM   0:00.27
postgres: liferay lportal 127.0.0.1(55101)  (postgres)
pgsql   70804  0.0  0.0 49724     0  ??  IWs  -         0:00.00
postgres: liferay lportal 127.0.0.1(62522)  (postgres)
pgsql   70805  0.0  0.0 49724     0  ??  IWs  -         0:00.00
postgres: liferay lportal 127.0.0.1(57897)  (postgres)
pgsql   70806  0.0  0.0 49724     0  ??  IWs  -         0:00.00
postgres: liferay lportal 127.0.0.1(51393)  (postgres)
pgsql   70894  0.0  0.8 49724  5908  ??  Is    2:30AM   0:00.67
postgres: liferay lportal 127.0.0.1(65399)  (postgres)
pgsql   70895  0.0  0.0 49724     0  ??  IWs  -         0:00.00
postgres: liferay lportal 127.0.0.1(54991)  (postgres)
pgsql   70896  0.0  0.7 49724  5412  ??  Is    2:30AM   0:00.65
postgres: liferay lportal 127.0.0.1(63123)  (postgres)
pgsql   70897  0.0  0.0 49724     0  ??  IWs  -         0:00.00
postgres: liferay lportal 127.0.0.1(63978)  (postgres)
pgsql   70898  0.0  0.8 49724  6284  ??  Is    2:30AM   0:00.59
postgres: liferay lportal 127.0.0.1(65359)  (postgres)
pgsql   70902  0.0  0.6 49724  4264  ??  Is    2:30AM   0:00.25
postgres: liferay lportal 127.0.0.1(50233)  (postgres)
pgsql   70903  0.0  0.6 49724  4924  ??  Is    2:30AM   0:00.41
postgres: liferay lportal 127.0.0.1(65401)  (postgres)
pgsql   70904  0.0  0.0 49724     0  ??  IWs  -         0:00.00
postgres: liferay lportal 127.0.0.1(63124)  (postgres)
pgsql   70905  0.0  0.0 49724     0  ??  IWs  -         0:00.00
postgres: liferay lportal 127.0.0.1(54153)  (postgres)
pgsql   70906  0.0  0.0 49724     0  ??  IWs  -         0:00.00
postgres: liferay lportal 127.0.0.1(63712)  (postgres)
pgsql   80297  0.0  0.7 49724  5044  ??  Is    6:22AM   0:00.28
postgres: liferay lportal 127.0.0.1(58431)  (postgres)
pgsql   80298  0.0  0.7 48700  5288  ??  Is    6:22AM   0:00.48
postgres: liferay lportal 127.0.0.1(50051)  (postgres)
pgsql   80299  0.0  1.0 49724  7600  ??  Is    6:22AM   0:00.30
postgres: liferay lportal 127.0.0.1(49678)  (postgres)
pgsql   80300  0.0  0.7 48700  5380  ??  Is    6:22AM   0:00.67
postgres: liferay lportal 127.0.0.1(58183)  (postgres)
pgsql   80301  0.0  0.6 49724  4748  ??  Is    6:22AM   0:00.37
postgres: liferay lportal 127.0.0.1(55792)  (postgres)
pgsql   93527  0.0  0.4 49724  3464  ??  Is   11:28AM   0:00.14
postgres: liferay lportal 127.0.0.1(54222)  (postgres)
pgsql   93528  0.0  0.0 48700     0  ??  IWs  -         0:00.00
postgres: liferay lportal 127.0.0.1(52385)  (postgres)
pgsql   93529  0.0  0.0 48700     0  ??  IWs  -         0:00.00
postgres: liferay lportal 127.0.0.1(59677)  (postgres)
pgsql   93530  0.0  0.0 48700     0  ??  IWs  -         0:00.00
postgres: liferay lportal 127.0.0.1(60016)  (postgres)
pgsql   93531  0.0  0.0 49724     0  ??  IWs  -         0:00.00
postgres: liferay lportal 127.0.0.1(56885)  (postgres)
pgsql   95330  0.0  0.9 49724  6812  ??  Is   12:05PM   0:00.18
postgres: liferay lportal 127.0.0.1(55050)  (postgres)
pgsql   95331  0.0  0.7 48700  5680  ??  Is   12:05PM   0:00.07
postgres: liferay lportal 127.0.0.1(53490)  (postgres)
pgsql   95332  0.0  0.8 49724  6572  ??  Is   12:05PM   0:00.47
postgres: liferay lportal 127.0.0.1(50029)  (postgres)
pgsql   95333  0.0  0.5 48700  3544  ??  Is   12:05PM   0:00.04
postgres: liferay lportal 127.0.0.1(65012)  (postgres)
pgsql   95334  0.0  0.8 48700  6236  ??  Is   12:05PM   0:00.06
postgres: liferay lportal 127.0.0.1(57130)  (postgres)

It seems I don't have enough memory to run my Liferay web portal,
there are 3 web portal instances are running, but some of  the primary
keys are failed to index properly:
..
16:40:18,175 WARN  [ResourceActionsUtil:564] Unable to obtain resource
actions for unknown portlet SampleContactUs
17:45:17,326 WARN  [PortalImpl:2948] Current URL
/c/portal/login?p_l_id=10404 generates exception: No Layout exists
with the primary key 10404
20:22:57,623 WARN  [PortalImpl:2948] Current URL
/c/portal/login?p_l_id=11432 generates exception: No Layout exists
with the primary key 11432
(END)

Your suggestion is very much appreciated.

Thanks