Size of oracle.exe

Question

Hi,
I have installed Oracle8i (8.1.7) for NT. I sized SGA to require about 15MB. But when the instance initiates, the oracle.exe process is getting about 30MB of memory! Do you know the reason??
Thanks in advanced,
Carlos

Answer 1

If you are running 32-bit Windows, then it doesn't matter that you've got 8GB physically in the box: that's a common over-configuration. A 32-bit Windows system can only see 4GB of RAM -and only 2GB of that is available to user-mode programs like Oracle.
If you use a /3GB switch, you can let user-mode programs see 3GB instead of 2GB. But that's your lot.
Unless you are also using a /PAE switch, though that has interesting interactions with the /3GB switch and everything else!
Let's assume you're using a bog-standard Windows environment with no odd boot-time switches. That means 2GB is your limit. And that's for everything Oracle might want to use it for: PGA and SGA alike. I don't know how big your PGA needs to be, but assume a worst-case: allow 50% for the PGA, and 50% for the SGA. That means your SGA_MAX_SIZE parameter should be no bigger than 1GB.
For some reason, you say this sort of thing is "not an option". That's fine: but then you live with the massive swapping to disk that will ensue if you don't keep within bounds. Your choice, really.
From memory, LOCK_SGA does indeed work. But if you're locking into memory an over-allocation of SGA, you'll just be making your paging problems worse.