Checkpoints

Hello,
I have written code to support multiple buffer pools in postgres 7.3.2.
Now i am looking at changing the sizes of these buffer pools, but first i
need to write all pages to disk.
I also need to incorporate this code into the backend instead of it being
a sql statement as it is now. I noticed that at a checkpoint, dirty pages
are written to disk. I was just wondering if someone can tell me how
postgres handles checkpoints and if it is advisable to do the sizing right
after a checkpoint?

Nailah
MSc Student