A, hopefully regular, update on what's happening with Qythyx.
Postgres shared_buffers Setting in Windows
Apparently Postgres on Windows doesn’t respond well to a high value for shared_buffers. This thread explains a little, but not definitively. Also, I found that setting the value to greater than 1GB (on a Windows Server 2008 x64 box with 8GB RAM) failed with this error in the event log:
%t FATAL: could not create shared memory segment: 8 %t DETAIL: Failed system call was MapViewOfFileEx.
So, for now I’m going with a conservative 32MB setting.