三.Oracle内存结构详解

三.一 Fixed SGA
1.结构及说明:
 Granule in SGA    
|==================|
|   Fixed  SGA     |-->Fixed SGA        *.Area containing all fixed variables                                             
|==================|                    *.Contains pointers to all other structures in SGA                                
|   Free Space     |                    *.Variable name, type, address and size determined when Oracle executable is linked
|- - - - - - - - - |                    *.Located at start of first granule of SGA        --SGA的第一个granule                                
| . . . . . . .    |
|==================|
|- - - - - -  -  - |                       20000000    Fixed SGA             --Head of Fixed SGA(select * from x$ksmfsv第一行的addr),与Fixed Area# 0地址相同
| . . . .  . . . . |                       xxxxxxxxx   Granule Directory  
| Buffer Cache     |                       xxxxxxxxx   Heap Headers
|. . . . . . .  . .|
|- - - - - - - - - |                   *.大小:
|- - - - - - - - - |                          SQL> select sum(KSMFSSIZ)/1024/1024  from x$ksmfsv;
|==================|                                                                            
|   Java Pool      |                          SUM(KSMFSSIZ)/1024/1024                           
|==================|                          -----------------------                           
|   Large Pool     |                               0.0903596878051758                           
|==================|
|- - - - - -  -  - |
| . . . .  . . . . |
| Shared Pool      |
|. . . . . . .  .  |
|==================|
| Redo Buffer      |
|==================|

 

2.Fixed SGA 相关内置视图:X$KSMFSV       
*.Externalises name, type, address and size of all variables in fixed SGA
  ADDR        RAW(4)         
  INDX        NUMBER         
  INST_ID      NUMBER       
  KSMFSNAM    VARCHAR2(64)                    -name                            
  KSMFSTYP    VARCHAR2(64)                    -type                       
  KSMFSADR    RAW(4)                          -addr                       
  KSMFSSIZ    NUMBER                          -size
Eg:
SQL> select * from x$ksmfsv;
ADDR           INDX    INST_ID KSMFSNAM                                                         KSMFSTYP                                                         KSMFSADR   KSMFSSIZ
-------- ---------- ---------- ---------------------------------------------------------------- ---------------------------------------------------------------- -------- ----------
0C54CF80          0          1 ksmsgf_                                                          ksmsgft                                                          20000000          4               --Fixed SGA Header Addr
0C54CF90          1          1 ksmvsg_