Oracle runs the sga1.7g method on a 32-bit System

When running a 32-bit Oracle database on a 32-bit or 64-bit platform, SGA is always limited, so that large memory machines cannot fully play a role, recently, I have found some documents on adjusting the largest SGA region. I have read the documents and I think they have gained a lot. I have summarized some of them, but they are not all complete. You are welcome to discuss them.

I will first post my summary of several platforms for discussion.

Expand SGA (1.7G or above) on RedHat ADVANCED SERVER2.1)

I. Objectives:
1. Increase SGA from 1.7G to 2.7G on a machine with more than 4 GB memory
2. compatible with database versions 8.1.7, 9.0.1, and 9.2.0
3. The entire SGA can be improved.
Ii. Restrictions:
1. Only allow local database startup and Shutdown
2. If too little virtual memory is saved for PGA, it will lead to a ORA-4030 Error
3. basic steps:
1. view the shel process id pid of the oracle user.
Ps-ef or echo $
2. Run the following process as the root user:
Echo 268435456>/proc/$ PID/mapped_base
The shell that generates the oracle process on the server
3. Modify the shmmax value. Run with root User
Echo 3000000000>/proc/sys/shmmax
4. reallocation of SGA
Shutdown immediate all oracle instances
Cd $ ORACLE_HOME/lib
Cp-a libserver9.a libserver9.a.org (back up the liberver9.a file)
Cd $ ORACLE_HOME/bin
Cp-a oracle oracle.org (back up oracle files)
Cd $ ORACLE_HOME/rdbms/lib
Genksms-s 0x15000000> ksms. s
Make-f ins_rdbms.mk ksms. o (compile the new sga address)
Make-f ins_rdbms.mk ioracle (relink)
After this change, you can support the 2.65G sga, which can improve the db_cache_size or db_block_buffers to improve the database buffer.

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