Today, the size of the lower SGA is adjusted, and the result is the following error when restarting the database.
Sql>alter system set sga_max_size=1024m scope=spfile;
sql> shutdown Immediate
Sql> Startup
Ora-00844:parameter not taking Memory_target to account
Ora-00851:sga_max_size 1073741824 cannot is set to more than Memory_target 784334848.
In Oracle checked, the original 11g added a parameter memory_target, its size is equal to PGA+SGA, when the size of the SGA is greater than Memory_target will be reported as the error.
Workaround:
You can directly modify the size of the memory_target in the Spflie file, but because you did not see the location of SPFile, do not know the specific location of SPFile, so you can only use the following methods
1.sqlplus/as SYSDBA
Sql>create pfile= '/home/oracle/pfile ' from SPFile;
Create a Pfile file, modify the Memory_target parameter in the Pfile file,
Then re-create the SPFile file
Sql>create spfile from pfile= '/home/oracle/pfile ';
Restart the results and report the following error
Sql> Startup
Ora-00845:memory_target not supported on the This system
This is due to the system Tmpfs less than memory_target, need to adjust the size of TMPFS
Vi/etc/fstab
Tmpfs/dev/shm Tmpfs defaults,size=2g 0 0
To modify the size of a size
Re-mount
Mount-o REMOUNT/DEV/SHM
Verification under
Df-h
Now it's time to start the database normally.
Sql> Startup
ORACLE instance started.
Total System Global area 1068937216 bytes
Fixed Size 2220200 bytes
Variable Size 943722328 bytes
Database buffers 117440512 bytes
Redo buffers 5554176 bytes
Database mounted.
Database opened.
Summing up, the subsequent adjustment of the SGA sequence is to adjust the size of the TMPFS, then adjust the size of memory_target, finally adjust the SGA, to ensure Tmpfs>memory_target >SGA+PGA
