|
; 1 2723 2723
--//10g:
SCOTT@test> select method,count(*),round(avg(TIME_ELA),0),sum(TIME_ELA) from job_times group by method order by 3 ;
METHOD COUNT(*) ROUND(AVG(TIME_ELA),0) SUM(TIME_ELA)
-------------------- ---------- ---------------------- -------------
id=unindex_name 1 1359 1359
id=unindex 1 1591 1591
--//真心搞不懂,回表反而更快一些.oracle许多东西真心搞不懂....
--//感觉如果访问数据块缓存数据块,没有阻塞无需要获取cbc latch吗?
5.附上gdb脚本:
--//11g版本:
$ cat latch11g.gdb
break kslgetl
commands
silent
printf "kslgetl %x, %d, %d, %d\n", $rdi, $rsi, $rdx, $rcx
c
end
break kslges
commands
silent
printf "kslges %x, %d, %d, %d\n", $rdi, $rsi, $rdx, $rcx
c
end
break skgpwwait
commands
silent
printf "skgpwwait %d, %d, %d, %d\n", $rdi, $rsi, $rdx, $rcx
c
end
break sskgpwwait
commands
silent
printf "sskgpwwait %d, %d, %d, %d\n", $rdi, $rsi, $rdx, $rcx
c
end
break semop
commands
silent
printf "semop %d, %d, %d, %d\n", $rdi, $rsi, $rdx, $rcx
c
end
#break *0x93f9ddc
# commands
# silent
# printf " spin count loop: %d %d %x\n", $rax,$rcx,$rip
# c
# end
##
break kslgetsl_w
commands
silent
printf "kslgetsl_w laddr:%x, willing:%d, where:%d, why:%d, mode:%d\n", $rdi, $rsi, $rdx, $rcx, $r8
c
end
break ksl_get_shared_latch
commands
silent
printf "ksl_get_shared_latch laddr:%x, willing:%d, where:%d, why:%d, mode:%d\n", $rdi, $rsi, $rdx, $rcx, $r8
c
end
break kslgess
commands
silent
printf "kslgess %x, %d, %d, %d\n", $rdi, $rsi, $rdx, $rcx
c
end
break kslskgs
commands
silent
printf "kslskgs %x, %d, %d, %d\n", $rdi, $rsi, $rdx, $rcx
c
end
break kslfre
commands
silent
printf "kslfre %x, %d, %d, %d\n |