[20191220]关于共享内存段相关问题.txt
[20191220]关于共享内存段相关问题.txt
--//我一直很好奇如果设置内核参数kernel.shmmax = 68719476736足够大,为什么我的测试实例还是建立3个共享内存段.
--//最后1个很特殊key=0xe8a8ec10,大小2M,我看过许多服务器只要key<>=0x00000000,最后都会有1个2M的共享内存段.
--//oracle为什么不是建立1个共享内存段呢?简单探究看看.
1.测试环境:
SYS@book> @ ver1
PORT_STRING VERSION BANNER
------------------------------ -------------- --------------------------------------------------------------------------------
x86_64/Linux 2.4.xx 11.2.0.4.0 Oracle Database 11g Enterprise Edition Release 11.2.0.4.0 - 64bit Production
SYS@book> show parameter sga_max_size
NAME TYPE VALUE
------------ ----------- -----
sga_max_size big integer 620M
--//Granule Size=4194304
$ ipcs -m
------ Shared Memory Segments --------
key shmid owner perms bytes nattch status
0x00000000 423034880 oracle 640 12582912 20
0x00000000 423067649 oracle 640 633339904 20
0xe8a8ec10 423100418 oracle 640 2097152 20
$ ipcs -m | awk '{print $5/1024/1024}' | grep -v "^0"
12
604
2
2.一些参数设置:
SYS@book> show parameter db_cache_size
NAME TYPE VALUE
------------- ----------- ------
db_cache_size big integer 408M
SYS@book> show parameter shared_pool_size
NAME TYPE VALUE
---------------- ----------- ------
shared_pool_size big integer 172M
SYS@book> show parameter java_pool_size
NAME TYPE VALUE
-------------- ----------- -----
java_pool_size big integer 12M
SYS@book> show parameter large_pool_size
NAME TYPE VALUE
--------------- ----------- ------
large_pool_size big integer 12M
SYS@book> show parameter sga_max_size
NAME TYPE VALUE
------------ ----------- -----
sga_max_size big integer 616M
--//注:我的测试环境一直采用手动管理.设置db_cache_size=408,shared_pool_size=172M,java_pool_size=12M,large_pool_size=12M,sga_max_size=616M.
--//剩下616-172-408-12-12= 12M.这12M正好和前面ipcs -m看到的第一共享内存段相对应.
3.测试与验证:
$ cat memalloc.sql
col component format a32
select min(BASEADDR), max(BASEADDR), count(1) Granules, sum(a.gransize)/1048576 MB, a.GRANFLAGS, component, a.GRANSTATE
from x$ksmge a, x$kmgsct b
where a.grantype = b.grantype (+)
group by a.GRANFLAGS, component, a.GRANSTATE
order by 1,2;
pause press enter .....
select a.BASEADDR, a.gransize, a.GRANFLAGS, b.component, a.GRANSTATE
from x$ksmge a, x$kmgsct b
where a.grantype = b.grantype (+)
order by 1,2;
SYS@book> @ memalloc
MIN(BASEADDR) MAX(BASEADDR) GRANULES MB GRANFLAGS COMPONENT GRANSTATE
---------------- ---------------- ---------- ---------- ---------- -------------------- ----------------
0000000060C00000 000000007A000000 102 408 4 DEFAULT buffer cache ALLOC
000000007A400000 000000007AC00000 3 12 4 java pool ALLOC
000000007B000000 000000007B800000 3 12 4 large pool ALLOC
000000007BC00000 0000000086400000 43 172 4 shared pool ALLOC
press enter .....
BASEADDR GRANSIZE GRANFLAGS COMPONENT GRANSTATE
---------------- ---------- ---------- -------------------------------- ----------------
0000000060C00000 4194304 4 DEFAULT buffer cache ALLOC
0000000061000000 4194304 4 DEFAULT buffer cache ALLOC
0000000061400000 4194304 4 DEFAULT buffer cache ALLOC
0000000061800000 4194304 4 DEFAULT buffer cache ALLOC
0000000061C00000 4194304 4 DEFAULT buffer cache ALLOC
0000000062000000 4194304 4 DEFAULT buffer cache ALLOC
0000000062400000 4194304 4 DEFAULT buffer cache ALLOC
0000000062800000 4194304 4 DEFAULT buffer cache ALLOC
0000000062C00000 4194304 4 DEFAULT buffer cache ALLOC
0000000063000000 4194304 4 DEFAULT buffer cache ALLOC
0000000063400000 4194304 4 DEFAULT buffer cache ALLOC
0000000063800000 4194304 4 DEFAULT buffer cache ALLOC
0000000063C00000 4194304 4 DEFAULT buffer cache ALLOC
0000000064000000 4194304 4 DEFAULT buffer cache ALLOC
0000000064400000 4194304 4 DEFAULT buffer cache ALLOC
0000000064800000 4194304 4 DEFAULT buffer cache ALLOC
0000000064C00000 4194304 4 DEFAULT buffer cache ALLOC
0000000065000000 4194304 4 DEFAULT buffer cache ALLOC
0000000065400000 4194304 4 DEFAULT buffer cache ALLOC
0000000065800000 4194304 4 DEFAULT buffer cache ALLOC
0000000065C00000 4194304 4 DEFAULT buffer cache ALLOC
0000000066000000 4194304 4 DEFAULT buffer cache ALLOC
0000000066400000 4194304 4 DEFAULT buffer cache ALLOC
0000000066800000 4194304 4 DEFAULT buffer cache ALLOC
0000000066C00000 4194304 4 DEFAULT buffer cache ALLOC
0000000067000000 4194304 4 DEFAULT buffer cache ALLOC
0000000067400000 4194304 4 DEFAULT buffer cache ALLOC
0000000067800000 4194304 4 DEFAULT buffer cache ALLOC
0000000067C00000 4194304 4 DEFAULT buffer cache ALLOC
0000000068000000 4194304 4 DEFAULT buffer cache ALLOC
0000000068400000 4194304 4 DEFAULT buffer cache ALLOC
0000000068800000 4194304 4 DEFAULT buffer cache ALLOC
0000000068C00000 4194304 4 DEFAULT buffer cache ALLOC
0000000069000000 4194304 4 DEFAULT buffer cache ALLOC
0000000069400000 4194304 4 DEFAULT buffer cache ALLOC
0000000069800000 4194304 4 DEFAULT buffer cache ALLOC
0000000069C00000 4194304 4 DEFAULT buffer cache ALLOC
000000006A000000 4194304 4 DEFAULT buffer cache ALLOC
000000006A400000 4194304 4 DEFAULT buffer cache ALLOC
000000006A800000 4194304 4 DEFAULT buffer cache ALLOC
000000006AC00000 4194304 4 DEFAULT buffer cache ALLOC
000000006B000000 4194304 4 DEFAULT buffer cache ALLOC
000000006B400000 4194304 4 DEFAULT buffer cache ALLOC
000000006B800000 4194304 4 DEFAULT buffer cache ALLOC
000000006BC00000 4194304 4 DEFAULT buffer cache ALLOC
000000006C000000 4194304 4 DEFAULT buffer cache ALLOC
000000006C400000 4194304 4 DEFAULT buffer cache ALLOC
000000006C800000 4194304 4 DEFAULT buffer cache ALLOC
000000006CC00000 4194304 4 DEFAULT buffer cache ALLOC
000000006D000000 4194304 4 DEFAULT buffer cache ALLOC
000000006D400000 4194304 4 DEFAULT buffer cache ALLOC
000000006D800000 4194304 4 DEFAULT buffer cache ALLOC
000000006DC00000 4194304 4 DEFAULT buffer cache ALLOC
000000006E000000 4194304 4 DEFAULT buffer cache ALLOC
000000006E400000 4194304 4 DEFAULT buffer cache ALLOC
000000006E800000 4194304 4 DEFAULT buffer cache ALLOC
000000006EC00000 4194304 4 DEFAULT buffer cache ALLOC
000000006F000000 4194304 4 DEFAULT buffer cache ALLOC
000000006F400000 4194304 4 DEFAULT buffer cache ALLOC
000000006F800000 4194304 4 DEFAULT buffer cache ALLOC
000000006FC00000 4194304 4 DEFAULT buffer cache ALLOC
0000000070000000 4194304 4 DEFAULT buffer cache ALLOC
0000000070400000 4194304 4 DEFAULT buffer cache ALLOC
0000000070800000 4194304 4 DEFAULT buffer cache ALLOC
0000000070C00000 4194304 4 DEFAULT buffer cache ALLOC
0000000071000000 4194304 4 DEFAULT buffer cache ALLOC
0000000071400000 4194304 4 DEFAULT buffer cache ALLOC
0000000071800000 4194304 4 DEFAULT buffer cache ALLOC
0000000071C00000 4194304 4 DEFAULT buffer cache ALLOC
0000000072000000 4194304 4 DEFAULT buffer cache ALLOC
0000000072400000 4194304 4 DEFAULT buffer cache ALLOC
0000000072800000 4194304 4 DEFAULT buffer cache ALLOC
0000000072C00000 4194304 4 DEFAULT buffer cache ALLOC
0000000073000000 4194304 4 DEFAULT buffer cache ALLOC
0000000073400000 4194304 4 DEFAULT buffer cache ALLOC
0000000073800000 4194304 4 DEFAULT buffer cache ALLOC
0000000073C00000 4194304 4 DEFAULT buffer cache ALLOC
0000000074000000 4194304 4 DEFAULT buffer cache ALLOC
0000000074400000 4194304 4 DEFAULT buffer cache ALLOC
0000000074800000 4194304 4 DEFAULT buffer cache ALLOC
0000000074C00000 4194304 4 DEFAULT buffer cache ALLOC
0000000075000000 4194304 4 DEFAULT buffer cache ALLOC
0000000075400000 4194304 4 DEFAULT buffer cache ALLOC
0000000075800000 4194304 4 DEFAULT buffer cache ALLOC
0000000075C00000 4194304 4 DEFAULT buffer cache ALLOC
0000000076000000 4194304 4 DEFAULT buffer cache ALLOC
0000000076400000 4194304 4 DEFAULT buffer cache ALLOC
0000000076800000 4194304 4 DEFAULT buffer cache ALLOC
0000000076C00000 4194304 4 DEFAULT buffer cache ALLOC
0000000077000000 4194304 4 DEFAULT buffer cache ALLOC
0000000077400000 4194304 4 DEFAULT buffer cache ALLOC
0000000077800000 4194304 4 DEFAULT buffer cache ALLOC
0000000077C00000 4194304 4 DEFAULT buffer cache ALLOC
0000000078000000 4194304 4 DEFAULT buffer cache ALLOC
0000000078400000 4194304 4 DEFAULT buffer cache ALLOC
0000000078800000 4194304 4 DEFAULT buffer cache ALLOC
0000000078C00000 4194304 4 DEFAULT buffer cache ALLOC
0000000079000000 4194304 4 DEFAULT buffer cache ALLOC
0000000079400000 4194304 4 DEFAULT buffer cache ALLOC
0000000079800000 4194304 4 DEFAULT buffer cache ALLOC
0000000079C00000 4194304 4 DEFAULT buffer cache ALLOC
000000007A000000 4194304 4 DEFAULT buffer cache ALLOC
000000007A400000 4194304 4 java pool ALLOC
000000007A800000 4194304 4 java pool ALLOC
000000007AC00000 4194304 4 java pool ALLOC
000000007B000000 4194304 4 large pool ALLOC
000000007B400000 4194304 4 large pool ALLOC
000000007B800000 4194304 4 large pool ALLOC
000000007BC00000 4194304 4 shared pool ALLOC
000000007C000000 4194304 4 shared pool ALLOC
000000007C400000 4194304 4 shared pool ALLOC
000000007C800000 4194304 4 shared pool ALLOC
000000007CC00000 4194304 4 shared pool ALLOC
000000007D000000 4194304 4 shared pool ALLOC
000000007D400000 4194304 4 shared pool ALLOC
000000007D800000 4194304 4 shared pool ALLOC
000000007DC00000 4194304 4 shared pool ALLOC
000000007E000000 4194304 4 shared pool ALLOC
000000007E400000 4194304 4 shared pool ALLOC
000000007E800000 4194304 4 shared pool ALLOC
000000007EC00000 4194304 4 shared pool ALLOC
000000007F000000 4194304 4 shared pool ALLOC
000000007F400000 4194304 4 shared pool ALLOC
000000007F800000 4194304 4 shared pool ALLOC
000000007FC00000 4194304 4 shared pool ALLOC
0000000080000000 4194304 4 shared pool ALLOC
0000000080400000 4194304 4 shared pool ALLOC
0000000080800000 4194304 4 shared pool ALLOC
0000000080C00000 4194304 4 shared pool ALLOC
0000000081000000 4194304 4 shared pool ALLOC
0000000081400000 4194304 4 shared pool ALLOC
0000000081800000 4194304 4 shared pool ALLOC
0000000081C00000 4194304 4 shared pool ALLOC
0000000082000000 4194304 4 shared pool ALLOC
0000000082400000 4194304 4 shared pool ALLOC
0000000082800000 4194304 4 shared pool ALLOC
0000000082C00000 4194304 4 shared pool ALLOC
0000000083000000 4194304 4 shared pool ALLOC
0000000083400000 4194304 4 shared pool ALLOC
0000000083800000 4194304 4 shared pool ALLOC
0000000083C00000 4194304 4 shared pool ALLOC
0000000084000000 4194304 4 shared pool ALLOC
0000000084400000 4194304 4 shared pool ALLOC
0000000084800000 4194304 4 shared pool ALLOC
0000000084C00000 4194304 4 shared pool ALLOC
0000000085000000 4194304 4 shared pool ALLOC
0000000085400000 4194304 4 shared pool ALLOC
0000000085800000 4194304 4 shared pool ALLOC
0000000085C00000 4194304 4 shared pool ALLOC
0000000086000000 4194304 4 shared pool ALLOC
0000000086400000 4194304 4 shared pool ALLOC
151 rows selected.
--//测试环境都是手动管理,内存分配都是连续的.
--//如果你仔细看MIN(BASEADDR),MAX(BASEADDR)可以发现是首尾相连的.
--//4*1024*1024 = 4194304 = = 0x400000
--//MAX(BASEADDR)+0x400000正好等于下一行的MIN(BASEADDR).
$ ps -ef | grep lgw[r]
oracle 19717 1 0 09:25 ? 00:00:02 ora_lgwr_book
$ cat /proc/19717/smaps | grep -A1 SYSV
60000000-60c00000 rw-s 00000000 00:0b 451543040 /SYSV00000000 (deleted)
Size: 12288 kB
--
60c00000-86800000 rw-s 00000000 00:0b 451575809 /SYSV00000000 (deleted)
Size: 618496 kB
--
86800000-86a00000 rw-s 00000000 00:0b 451608578 /SYSVe8a8ec10 (deleted)
Size: 2048 kB
--//这些信息也可以对上.
--//还可以看出执行@ memalloc看到的内容就是ipcs -m的第2个共享内存段.
--//查询v$sgainfo
SYS@book> select * from v$sgainfo ;
NAME BYTES RES
---------------------------------------- ---------- ---
Fixed SGA Size 2255872 No
Redo Buffers 7487488 No
Buffer Cache Size 427819008 Yes
Shared Pool Size 180355072 Yes
Large Pool Size 12582912 Yes
Java Pool Size 12582912 Yes
Streams Pool Size 0 Yes
Shared IO Pool Size 0 Yes
Granule Size 4194304 No
Maximum SGA Size 643084288 No
Startup overhead in Shared Pool 133446832 No
Free SGA Memory Available 0
12 rows selected.
--//Fixed SGA Size+Redo Buffers = 2255872+7487488 = 9743360, 9743360/1024/1024 = 9.29M.
--//从视图v$sgainfo可以看出Fixed SGA Size,Redo Buffers一定在ipcs -m输出的第1个共享内存段内.
--//你可以尝试修改log_buffer大小,变化一定在ipcs -m输出的第1个共享内存段内.我不贴上来了.
--//而Fixed SGA Size与参数processes存在密切关系.
4.继续测试:
--//链接:http://blog.itpub.net/267265/viewspace-2667945/=>[20191211]11g streams_pool_size参数.txt
$ expdp scott/book
...
--//再看oracle内存分配情况:
SYS@book> @ memalloc
MIN(BASEADDR) MAX(BASEADDR) GRANULES MB GRANFLAGS COMPONENT GRANSTATE
---------------- ---------------- ---------- ---------- ---------- -------------------------------- ----------------
0000000060C00000 0000000061C00000 5 20 4 streams pool ALLOC
0000000062000000 0000000086400000 48 192 4 shared pool ALLOC
0000000063400000 000000007A000000 92 368 4 DEFAULT buffer cache ALLOC
000000007A400000 000000007AC00000 3 12 4 java pool ALLOC
000000007B000000 000000007B800000 3 12 4 large pool ALLOC
press enter .....
BASEADDR GRANSIZE GRANFLAGS COMPONENT GRANSTATE
---------------- ---------- ---------- -------------------------------- ----------------
0000000060C00000 4194304 4 streams pool ALLOC
0000000061000000 4194304 4 streams pool ALLOC
0000000061400000 4194304 4 streams pool ALLOC
0000000061800000 4194304 4 streams pool ALLOC
0000000061C00000 4194304 4 streams pool ALLOC
0000000062000000 4194304 4 shared pool ALLOC
0000000062400000 4194304 4 shared pool ALLOC
0000000062800000 4194304 4 shared pool ALLOC
0000000062C00000 4194304 4 shared pool ALLOC
0000000063000000 4194304 4 shared pool ALLOC
0000000063400000 4194304 4 DEFAULT buffer cache ALLOC
0000000063800000 4194304 4 DEFAULT buffer cache ALLOC
0000000063C00000 4194304 4 DEFAULT buffer cache ALLOC
0000000064000000 4194304 4 DEFAULT buffer cache ALLOC
0000000064400000 4194304 4 DEFAULT buffer cache ALLOC
0000000064800000 4194304 4 DEFAULT buffer cache ALLOC
0000000064C00000 4194304 4 DEFAULT buffer cache ALLOC
0000000065000000 4194304 4 DEFAULT buffer cache ALLOC
0000000065400000 4194304 4 DEFAULT buffer cache ALLOC
0000000065800000 4194304 4 DEFAULT buffer cache ALLOC
0000000065C00000 4194304 4 DEFAULT buffer cache ALLOC
0000000066000000 4194304 4 DEFAULT buffer cache ALLOC
0000000066400000 4194304 4 DEFAULT buffer cache ALLOC
0000000066800000 4194304 4 DEFAULT buffer cache ALLOC
0000000066C00000 4194304 4 DEFAULT buffer cache ALLOC
0000000067000000 4194304 4 DEFAULT buffer cache ALLOC
0000000067400000 4194304 4 DEFAULT buffer cache ALLOC
0000000067800000 4194304 4 DEFAULT buffer cache ALLOC
0000000067C00000 4194304 4 DEFAULT buffer cache ALLOC
0000000068000000 4194304 4 DEFAULT buffer cache ALLOC
0000000068400000 4194304 4 DEFAULT buffer cache ALLOC
0000000068800000 4194304 4 DEFAULT buffer cache ALLOC
0000000068C00000 4194304 4 DEFAULT buffer cache ALLOC
0000000069000000 4194304 4 DEFAULT buffer cache ALLOC
0000000069400000 4194304 4 DEFAULT buffer cache ALLOC
0000000069800000 4194304 4 DEFAULT buffer cache ALLOC
0000000069C00000 4194304 4 DEFAULT buffer cache ALLOC
000000006A000000 4194304 4 DEFAULT buffer cache ALLOC
000000006A400000 4194304 4 DEFAULT buffer cache ALLOC
000000006A800000 4194304 4 DEFAULT buffer cache ALLOC
000000006AC00000 4194304 4 DEFAULT buffer cache ALLOC
000000006B000000 4194304 4 DEFAULT buffer cache ALLOC
000000006B400000 4194304 4 DEFAULT buffer cache ALLOC
000000006B800000 4194304 4 DEFAULT buffer cache ALLOC
000000006BC00000 4194304 4 DEFAULT buffer cache ALLOC
000000006C000000 4194304 4 DEFAULT buffer cache ALLOC
000000006C400000 4194304 4 DEFAULT buffer cache ALLOC
000000006C800000 4194304 4 DEFAULT buffer cache ALLOC
000000006CC00000 4194304 4 DEFAULT buffer cache ALLOC
000000006D000000 4194304 4 DEFAULT buffer cache ALLOC
000000006D400000 4194304 4 DEFAULT buffer cache ALLOC
000000006D800000 4194304 4 DEFAULT buffer cache ALLOC
000000006DC00000 4194304 4 DEFAULT buffer cache ALLOC
000000006E000000 4194304 4 DEFAULT buffer cache ALLOC
000000006E400000 4194304 4 DEFAULT buffer cache ALLOC
000000006E800000 4194304 4 DEFAULT buffer cache ALLOC
000000006EC00000 4194304 4 DEFAULT buffer cache ALLOC
000000006F000000 4194304 4 DEFAULT buffer cache ALLOC
000000006F400000 4194304 4 DEFAULT buffer cache ALLOC
000000006F800000 4194304 4 DEFAULT buffer cache ALLOC
000000006FC00000 4194304 4 DEFAULT buffer cache ALLOC
0000000070000000 4194304 4 DEFAULT buffer cache ALLOC
0000000070400000 4194304 4 DEFAULT buffer cache ALLOC
0000000070800000 4194304 4 DEFAULT buffer cache ALLOC
0000000070C00000 4194304 4 DEFAULT buffer cache ALLOC
0000000071000000 4194304 4 DEFAULT buffer cache ALLOC
0000000071400000 4194304 4 DEFAULT buffer cache ALLOC
0000000071800000 4194304 4 DEFAULT buffer cache ALLOC
0000000071C00000 4194304 4 DEFAULT buffer cache ALLOC
0000000072000000 4194304 4 DEFAULT buffer cache ALLOC
0000000072400000 4194304 4 DEFAULT buffer cache ALLOC
0000000072800000 4194304 4 DEFAULT buffer cache ALLOC
0000000072C00000 4194304 4 DEFAULT buffer cache ALLOC
0000000073000000 4194304 4 DEFAULT buffer cache ALLOC
0000000073400000 4194304 4 DEFAULT buffer cache ALLOC
0000000073800000 4194304 4 DEFAULT buffer cache ALLOC
0000000073C00000 4194304 4 DEFAULT buffer cache ALLOC
0000000074000000 4194304 4 DEFAULT buffer cache ALLOC
0000000074400000 4194304 4 DEFAULT buffer cache ALLOC
0000000074800000 4194304 4 DEFAULT buffer cache ALLOC
0000000074C00000 4194304 4 DEFAULT buffer cache ALLOC
0000000075000000 4194304 4 DEFAULT buffer cache ALLOC
0000000075400000 4194304 4 DEFAULT buffer cache ALLOC
0000000075800000 4194304 4 DEFAULT buffer cache ALLOC
0000000075C00000 4194304 4 DEFAULT buffer cache ALLOC
0000000076000000 4194304 4 DEFAULT buffer cache ALLOC
0000000076400000 4194304 4 DEFAULT buffer cache ALLOC
0000000076800000 4194304 4 DEFAULT buffer cache ALLOC
0000000076C00000 4194304 4 DEFAULT buffer cache ALLOC
0000000077000000 4194304 4 DEFAULT buffer cache ALLOC
0000000077400000 4194304 4 DEFAULT buffer cache ALLOC
0000000077800000 4194304 4 DEFAULT buffer cache ALLOC
0000000077C00000 4194304 4 DEFAULT buffer cache ALLOC
0000000078000000 4194304 4 DEFAULT buffer cache ALLOC
0000000078400000 4194304 4 DEFAULT buffer cache ALLOC
0000000078800000 4194304 4 DEFAULT buffer cache ALLOC
0000000078C00000 4194304 4 DEFAULT buffer cache ALLOC
0000000079000000 4194304 4 DEFAULT buffer cache ALLOC
0000000079400000 4194304 4 DEFAULT buffer cache ALLOC
0000000079800000 4194304 4 DEFAULT buffer cache ALLOC
0000000079C00000 4194304 4 DEFAULT buffer cache ALLOC
000000007A000000 4194304 4 DEFAULT buffer cache ALLOC
000000007A400000 4194304 4 java pool ALLOC
000000007A800000 4194304 4 java pool ALLOC
000000007AC00000 4194304 4 java pool ALLOC
000000007B000000 4194304 4 large pool ALLOC
000000007B400000 4194304 4 large pool ALLOC
000000007B800000 4194304 4 large pool ALLOC
000000007BC00000 4194304 4 shared pool ALLOC
000000007C000000 4194304 4 shared pool ALLOC
000000007C400000 4194304 4 shared pool ALLOC
000000007C800000 4194304 4 shared pool ALLOC
000000007CC00000 4194304 4 shared pool ALLOC
000000007D000000 4194304 4 shared pool ALLOC
000000007D400000 4194304 4 shared pool ALLOC
000000007D800000 4194304 4 shared pool ALLOC
000000007DC00000 4194304 4 shared pool ALLOC
000000007E000000 4194304 4 shared pool ALLOC
000000007E400000 4194304 4 shared pool ALLOC
000000007E800000 4194304 4 shared pool ALLOC
000000007EC00000 4194304 4 shared pool ALLOC
000000007F000000 4194304 4 shared pool ALLOC
000000007F400000 4194304 4 shared pool ALLOC
000000007F800000 4194304 4 shared pool ALLOC
000000007FC00000 4194304 4 shared pool ALLOC
0000000080000000 4194304 4 shared pool ALLOC
0000000080400000 4194304 4 shared pool ALLOC
0000000080800000 4194304 4 shared pool ALLOC
0000000080C00000 4194304 4 shared pool ALLOC
0000000081000000 4194304 4 shared pool ALLOC
0000000081400000 4194304 4 shared pool ALLOC
0000000081800000 4194304 4 shared pool ALLOC
0000000081C00000 4194304 4 shared pool ALLOC
0000000082000000 4194304 4 shared pool ALLOC
0000000082400000 4194304 4 shared pool ALLOC
0000000082800000 4194304 4 shared pool ALLOC
0000000082C00000 4194304 4 shared pool ALLOC
0000000083000000 4194304 4 shared pool ALLOC
0000000083400000 4194304 4 shared pool ALLOC
0000000083800000 4194304 4 shared pool ALLOC
0000000083C00000 4194304 4 shared pool ALLOC
0000000084000000 4194304 4 shared pool ALLOC
0000000084400000 4194304 4 shared pool ALLOC
0000000084800000 4194304 4 shared pool ALLOC
0000000084C00000 4194304 4 shared pool ALLOC
0000000085000000 4194304 4 shared pool ALLOC
0000000085400000 4194304 4 shared pool ALLOC
0000000085800000 4194304 4 shared pool ALLOC
0000000085C00000 4194304 4 shared pool ALLOC
0000000086000000 4194304 4 shared pool ALLOC
0000000086400000 4194304 4 shared pool ALLOC
151 rows selected.
--//注:这里看shared pool被分成2部分.
--//DEFAULT buffer cache=408-368 = 40M.前面40M被分给streams pool=20M,shared poo=20M.
SYS@book> select * from v$sgainfo ;
NAME BYTES RES
---------------------------------------- ---------- ---
Fixed SGA Size 2255872 No
Redo Buffers 7487488 No
Buffer Cache Size 385875968 Yes
Shared Pool Size 201326592 Yes
Large Pool Size 12582912 Yes
Java Pool Size 12582912 Yes
Streams Pool Size 20971520 Yes
Shared IO Pool Size 0 Yes
Granule Size 4194304 No
Maximum SGA Size 643084288 No
Startup overhead in Shared Pool 133446832 No
Free SGA Memory Available 0
12 rows selected.
--//注:与我链接测试不同http://blog.itpub.net/267265/viewspace-2667945/,我当时Shared Pool Size没有变化.
5.总结:
--//也就是从以上测试可以看出,oracle启动建立的第1个共享内存段主要包括Fixed SGA Size +Redo Buffers.可以大概猜测
--//oracle启动为什么会出现这样的情况.
