High sys calls (Oracle) ?

we have one Solaris 10 (sparc) server with Oracle (only) working on it. One day we had the following high syscalls:

08:40:02      22       6       0      72
08:50:02      23       7       0      69
09:00:01      25       7       0      68
09:10:01      26       7       0      66
09:20:02      30       7       0      63
09:30:02      23      14       0      62
09:40:01      27      13       0      60
09:50:02      25      13       0      63
10:00:02      24      21       0      55
10:10:04      26      21       0      52
10:20:01      28      26       0      46
10:30:02      25      15       0      61
10:40:02      28      20       0      51
10:50:02      34      26       0      40
11:00:02      34      16       0      50
11:10:02      34      11       0      56
11:20:02      41       9       0      49
11:30:02      35       9       0      56
11:40:02      40      10       0      50
11:50:02      44       9       0      47
12:00:02      41       8       0      51
12:10:02      44       9       0      46
12:20:01      38       7       0      54
12:30:02      38       8       0      54

This is unusual for this server and I wasn't at the moment of these high sys calls close to this server (if I was I would use dtrace to check what caused syscall). Unfortunatelly we have only historical data. Does anybody know if there is any operation(s) in Oracle which could cause high syscalls ? Is it possible to confirm that using Oracle statistics tables ?

Regards
Przemyslaw Bak

--
http://www.freelists.org/webpage/oracle-l