I work on an 815 DB and we have a web site runnning . My DB is good at normal days but sometimes when we have a high hit rate on the web site , The DB hangs for that time (slows to such an extent that the sqlplus login on command level also takes 1 minute) . Please help me and let me know if anybody has faced such a situation and what can i do to prevent it .

I am putting my /etc/system file for refelrence . Please let me know if there is anything wrong or incorrect in this

set shmsys:shminfo_shmmax=1073741824
set shmsys:shminfo_shmmin=1
set shmsys:shminfo_shmmni = 100
set shmsys:shminfo_shmseg = 10
set semsys:seminfo_semmni = 100
set semsys:seminfo_semmsl = 1600
set semsys:seminfo_semmns = 5000
set semsys:seminfo_semopm = 100
set semsys:seminfo_semvmx = 32767