Oracle内存结构(四)----如何获得Oracle各内存段的内部信息
2020-03-09 22:48:14
供稿：网友
taking heapdumps:
heapdumps可以在当前会话通过使用命令alter system set events或者通过oradebug events命令.heapdumps将会被写成一个trace文件到进程dump的目录下面(udump),它所包含的信息跟相应的表x$相同.
事件的语法是immediate trace name heapdump level n. level的值可以是如下:1,2,4,8,32.这些值分别对应dump出来的信息是pga,sga,uga,cga,large pool.
subheap dump事件的语法是immediate trace name heapdump_addr level n. n是一个十六位的subheap地址描述符.这些地址可以从ksm x$表中的字段ksmchpar得到,也可以从heapdump的文件中的字符串ds=得到
sql>alter session set tracefile_identifier=test
sql>alter session set events ‘immediate trace name heapdump level 1’;
然后到$oracle_home/admin/udump下找到一个文件名含有test的文件用记事本打开,dump出来的文件大概如下:
*** 2004-11-30 10:42:09.000
******************************************************
heap dump heap name="pga heap" desc=067d1fe8---红色可以看到我们dump的是哪个heap,这里dump的pga.
extent sz=0x213c alt=84 het=32767 rec=0 flg=2 opc=2
parent=00000000 owner=00000000 nex=00000000 xsz=0x25b8
extent 0 addr=07beb9a4---extent号以及它的地址
chunk 7beb9ac sz= 9648 freeable "kcrr kcrrpdi ar"
chunk 7beb9ac---chunk地址
sz= 9648---这个chunk的size,以bytes为单位.
freeable----这个chunk的类型
"kcrr kcrrpdi ar"----这个chunk的用处描述
extent 1 addr=07be9854
chunk 7be985c sz= 8500 perm "perm " alo=7524
extent 2 addr=07be7474
chunk 7be747c sz= 9156 freeable "fixed uga "
extent 3 addr=07be5324
chunk 7be532c sz= 3764 perm "perm " alo=3764
chunk 7be61e0 sz= 2788 freeable "alloc environm " ds=07b6adf4
ds=07b6adf4-----这个是前面讲到的subheapdump的level,subheap的地址描述
chunk 7be6cc4 sz= 540 freeable "kopolal dvoid "
chunk 7be6ee0 sz= 288 freeable "kopolal dvoid "
chunk 7be7000 sz= 220 freeable "kopolal dvoid "
chunk 7be70dc sz= 900 freeable "kopolal dvoid "
extent 4 addr=07be31d4
chunk 7be31dc sz= 8440 perm "perm " alo=8440
chunk 7be52d4 sz= 60 free " "
extent 5 addr=07be1084
chunk 7be108c sz= 7096 perm "perm " alo=7096
chunk 7be2c44 sz= 1140 perm "perm " alo=1140
chunk 7be30b8 sz= 28 free " "
chunk 7be30d4 sz= 36 freeable "koh-kghu call h"
chunk 7be30f8 sz= 200 freeable "pls cca hp desc"
extent 6 addr=07bb0034
chunk 7bb003c sz= 3052 perm "perm " alo=3052
chunk 7bb0c28 sz= 404 perm "perm " alo=404
chunk 7bb0dbc sz= 56 free " "
chunk 7bb0df4 sz= 92 freeable "joxp heap "
chunk 7bb0e50 sz= 36 freeable "external name "
chunk 7bb0e74 sz= 36 freeable "kzsna:login nam"
chunk 7bb0e98 sz= 17012 freeable "ksm stack "
extent 7 addr=07b68d34
chunk 7b68d3c sz= 2000 perm "perm " alo=2000
chunk 7b6950c sz= 152 perm "perm " alo=152
chunk 7b695a4 sz= 116 free " "
chunk 7b69618 sz= 540 freeable "kopolal dvoid "
chunk 7b69834 sz= 92 freeable "ksfq heap descr"
chunk 7b69890 sz= 16 freeable "ksfh indicator "
chunk 7b698a0 sz= 4144 recreate "alloc environm " latch=00000000
ds 7b6adf4 sz= 6932 ct= 2
7be61e0 sz= 2788
chunk 7b6a8d0 sz= 1424 freeable "kpuinit env han"
total heap size = 81976----这个heap的size,应该是以kb为单位.
free lists:-----这个pga free lists的一些信息
bucket 0 size=44---bucket号以及其对应的free chunks size,这个size以bytes为单位.
chunk 7bb0dbc sz= 56 free " "
chunk 7be52d4 sz= 60 free " "
chunk 7be30b8 sz= 28 free " "
bucket 1 size=76
bucket 2 size=96
chunk 7b695a4 sz= 116 free " "
bucket 3 size=140
bucket 4 size=236
bucket 5 size=268
bucket 6 size=524
bucket 7 size=1036
bucket 8 size=2060
bucket 9 size=4108
bucket 10 size=8204
bucket 11 size=16396
bucket 12 size=32780
bucket 13 size=65548
bucket 14 size=131084
bucket 15 size=262156
bucket 16 size=524300
bucket 17 size=2097164
total free space = 260---以kb为单位.
unpinned recreatable chunks (lru first):
permanent chunks:
chunk 7be985c sz= 8500 perm "perm " alo=7524
chunk 7be532c sz= 3764 perm "perm " alo=3764
chunk 7b6950c sz= 152 perm "perm " alo=152
chunk 7bb0c28 sz= 404 perm "perm " alo=404
chunk 7be31dc sz= 8440 perm "perm " alo=8440
chunk 7be2c44 sz= 1140 perm "perm " alo=1140
chunk 7bb003c sz= 3052 perm "perm " alo=3052
chunk 7be108c sz= 7096 perm "perm " alo=7096
chunk 7b68d3c sz= 2000 perm "perm " alo=2000
permanent space = 34548---以kb为单位.
******************************************************
******************************************************
heap dump heap name="top call heap" desc=067d46d8
heap name="top call heap"----这个pga中的cga信息
extent sz=0x213c alt=92 het=32767 rec=0 flg=2 opc=3
parent=00000000 owner=00000000 nex=00000000 xsz=0xfffc
extent 0 addr=07bf0004
chunk 7bf000c sz= 32828 perm "perm " alo=136
chunk 7bf8048 sz= 30552 free " "
chunk 7bff7a0 sz= 1072 recreate "callheap " latch=00000000
ds 67d3d00 sz= 1072 ct= 1
chunk 7bffbd0 sz= 1072 recreate "callheap " latch=00000000
ds 67d3d68 sz= 1072 ct= 1
total heap size = 65524
free lists:
bucket 0 size=44
bucket 1 size=76
bucket 2 size=96
bucket 3 size=140
bucket 4 size=236
bucket 5 size=268
bucket 6 size=524
bucket 7 size=1036
bucket 8 size=2060
bucket 9 size=4108
bucket 10 size=8204
bucket 11 size=16396
chunk 7bf8048 sz= 30552 free " "
bucket 12 size=32780
bucket 13 size=65548
bucket 14 size=131084
bucket 15 size=262156
bucket 16 size=524300
bucket 17 size=2097164
total free space = 30552
unpinned recreatable chunks (lru first):
permanent chunks:
chunk 7bf000c sz= 32828 perm "perm " alo=136
permanent space = 32828
******************************************************
******************************************************
heap dump heap name="top uga heap" desc=067d47f8
heap name="top uga heap"---这个pga中的uga信息
extent sz=0xffdc alt=92 het=32767 rec=0 flg=2 opc=3
parent=00000000 owner=00000000 nex=00000000 xsz=0x1fffc
extent 0 addr=07c00004
chunk 7c0000c sz= 48 free " "
chunk 7c0003c sz= 65476 recreate "session heap " latch=00000000
ds 7be7490 sz= 65476 ct= 1
total heap size = 65524
free lists:
bucket 0 size=44
chunk 7c0000c sz= 48 free " "
bucket 1 size=76
bucket 2 size=96
bucket 3 size=140
bucket 4 size=236
bucket 5 size=268
bucket 6 size=524
bucket 7 size=1036
bucket 8 size=2060
bucket 9 size=4108
bucket 10 size=8204
bucket 11 size=16396
bucket 12 size=32780
bucket 13 size=65548
bucket 14 size=131084
bucket 15 size=262156
bucket 16 size=524300
bucket 17 size=2097164
total free space = 48
unpinned recreatable chunks (lru first):
permanent chunks:
permanent space = 0
******************************************************
这上面有一些还没搞清楚.所以在这里就没做解释.
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