[sqlite] MMAP

[John Stanton]

I wonder if members can help me with some advice.  I have a program 
which is a multi-threaded application server with Sqlite embedded which 
runs on Unix and Windows.  For an i/o buffer per thread I have the idea 
of using a mmap'd file so that it can be transferred using 
sendfile/TransmitFile with minimum overhead and no buffer shadowing. 
The program design is such that there is a pool of inactive threads 
waiting for a connection, and that pool could be quite large.  Each one 
would have a mmap'd file with an open fd involved.

Does anyone know the performance impact of having a considerable number 
of mmap'd files attached to a single process in Unix/Linux and Windows? 
 Has anyone tried such a strategy?  My guess is that the impact is not 
great, but I have no evidence in support.
JS