Xapian under 360 MB VPS

Hello,

I wish to get some feedback on the use of Xapian in a virtual machine hosting plan with 360MB. The processes to
share the 360MB will be the following:

0. nginx web server as front (estimated 5MB)

1. custom C++ FastCGI for dynamic requests (estimated 10MB)

2. Xapian writer (1 process and 1 thread)

3. Xapian readers (1 process with n threads for n readers)

4. PostgreSQL (estimated 50MB or lower)

That leaves about 300MB for Xapian and the rest of the Linux OS. The main UI will be a Google style search box.

Questions:

0. How would you configure Xapian for such low memory systems (e.g. how many readers, flush threshold for writer)?

1. Will file handle limitation be a problem for multithreaded Xapian reader?

2. What are advantages of multiprocess readers (compared to multithreaded) aside from crash isolation

Thanks so much!
Marlon