Starting with 12c, Oracle Database uses the Optimized Shared Memory (OSM) model of Oracle Solaris on Oracle Solaris 10 1/13 or later and Oracle Solaris 11 SRU 7.5 or later systems to implement Automatic Memory Management.
OSM allows dynamic resizing of System Global Area (SGA) without restarting the instance. It does not use the oradism utility and swap disk space. OSM is NUMA-optimized.
Total System Global Area 1258291200 bytes
Fixed Size 3003176 bytes
Variable Size 905972952 bytes
Database Buffers 218103808 bytes
Redo Buffers 13770752 bytes
In-Memory Area 117440512 bytes
SQL> show parameter memory_target
NAME TYPE VALUE
------------------------------------ ----------- ------------------------------
memory_target big integer 1200M
SQL> show parameter memory_max_target
NAME TYPE VALUE
------------------------------------ ----------- ------------------------------
memory_max_target big integer 1200M
Dump of system resources acquired for SHARED GLOBAL AREA (SGA)
Available system pagesizes:
4K, 2048K
Supported system pagesize(s):
PAGESIZE AVAILABLE_PAGES EXPECTED_PAGES ALLOCATED_PAGES ERROR(s)
4K Configured 2 2 NONE
2048K Configured 601 601 NONE
oracle@solaris:~$ ipcs -dm
IPC status from <running system> as of Tuesday, October 7, 2014 08:39:35 PM SGT
T ID KEY MODE OWNER GROUP ALLOC
Shared Memory:
m 25 0x6a4bcd4 --rw-r----- oracle oinstall -
m 24 0x0 --rw-r----- oracle oinstall 14680064
m 23 0x0 --rw-r----- oracle oinstall 33554432
m 22 0x0 --rw-r----- oracle oinstall 1123966976
m 21 0x0 --rw-r----- oracle oinstall 83886080
m 20 0x0 --rw-r----- oracle oinstall 4194304
If the column ALLOC shows an integer, it specifies that OSM is in use. If the column ALLOC shows a hyphen, it specifies that OSM is not in use.
oracle@solaris:~$ ipcs -im
IPC status from <running system> as of Tuesday, October 7, 2014 08:38:28 PM SGT
T ID KEY MODE OWNER GROUP ISMATTCH
Shared Memory:
m 25 0x6a4bcd4 --rw-r----- oracle oinstall 46
m 24 0x0 --rw-r----- oracle oinstall 46
m 23 0x0 --rw-r----- oracle oinstall 46
m 22 0x0 --rw-r----- oracle oinstall 46
m 21 0x0 --rw-r----- oracle oinstall 46
m 20 0x0 --rw-r----- oracle oinstall 46
SQL> select (14680064+33554432+1123966976+83886080+4194304)/1024/1024 from dual;
(14680064+33554432+1123966976+83886080+4194304)/1024/1024
---------------------------------------------------------
1201.89844
SQL> alter system set memory_max_target=1232M;
alter system set memory_max_target=1232M
*
ERROR at line 1:
ORA-02095: specified initialization parameter cannot be modified
SQL> alter system set memory_max_target=1232M scope=spfile;
System altered.
SQL> startup
ORACLE instance started.
Total System Global Area 1291845632 bytes
Fixed Size 3003272 bytes
Variable Size 939527288 bytes
Database Buffers 218103808 bytes
Redo Buffers 13770752 bytes
In-Memory Area 117440512 bytes
Database mounted.
All SGA segments were allocated at startup
**********************************************************************
Dump of system resources acquired for SHARED GLOBAL AREA (SGA)
Available system pagesizes:
4K, 2048K
Supported system pagesize(s):
PAGESIZE AVAILABLE_PAGES EXPECTED_PAGES ALLOCATED_PAGES ERROR(s)
4K Configured 2 2 NONE
2048K Configured 617 617 NONE
**********************************************************************
oracle@solaris:~$ ipcs -dm
IPC status from <running system> as of Tuesday, October 7, 2014 08:53:02 PM SGT
T ID KEY MODE OWNER GROUP ALLOC
Shared Memory:
m 268435459 0x6a4bcd4 --rw-r----- oracle oinstall -
m 268435458 0x0 --rw-r----- oracle oinstall 14680064
m 268435457 0x0 --rw-r----- oracle oinstall 33554432
m 268435456 0x0 --rw-r----- oracle oinstall 1157496832
m 251658303 0x0 --rw-r----- oracle oinstall 83886080
m 251658302 0x0 --rw-r----- oracle oinstall 4194304
SQL> select (14680064+33554432+1157496832+83886080+4194304)/1024/1024 from dual;
(14680064+33554432+1157496832+83886080+4194304)/1024/1024
---------------------------------------------------------
1233.875
SQL> alter system set memory_target=1232M;
System altered.
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