Solaris excesive semaphores usage.

Hi all:

Versions:

PostgreSQL 8.0.1
SunOS relayprod02 5.9 Generic_118558-19 sun4u sparc SUNW,Sun-Fire-V440 
-> Solaris 9 on Sparc processor.


We are running java app over PostgreSQL. Everything works fine but we 
detected high semaphore usage during a heavy query process.

This is result of "sar -m" command.

Time         msg/s  sema/s
16:59:00    0.00   39.68
16:59:05    0.00   93.01
16:59:10    0.00   40.48
16:59:15    0.00   26.80
16:59:20    0.00  179.20
16:59:25    0.00  184.40
16:59:30    0.00  108.58
16:59:35    0.00  218.84
16:59:40    0.00  124.40
16:59:45    0.00 1328.14
16:59:50    0.00 1335.47
16:59:55    0.00 1289.60
17:00:00    0.00 1466.40
17:00:05    0.00 21004.59
17:00:10    0.00 24332.60
17:00:15    0.00 18206.81
17:00:20    0.00 29127.46
17:00:25    0.00 26930.94
17:00:30    0.00 5771.20
17:00:35    0.00 4503.60
17:00:40    0.00 4282.80
17:00:45    0.00 18480.80
17:00:50    0.00 24908.40
17:00:55    0.00 28279.20
17:01:00    0.00 30194.81
17:01:05    0.00 9260.12
17:01:10    0.00 1604.00
17:01:15    0.00 1378.84
17:01:20    0.00 1310.62
17:01:25    0.00  133.20
17:01:30    0.00   66.60
17:01:35    0.00   42.51
17:01:40    0.00  120.00
17:01:45    0.00   38.08
17:01:50    0.00   49.90
17:01:55    0.00   51.30
17:02:00    0.00   72.65
17:02:05    0.00   44.89


During this time, java app launch several thousands of select sentences.

Why is happening this amount of semaphore usage if we are not writing, 
only reading???

Thank you.