the number of child tables --table partitioning

Hey,

Is there a suggested number of child tables for table partitioning, I ran a stress test on a master
table (with 800 thousand rows), trying to create 500,000 child tables for it, each child table has 2
indexes and 3 constraints (Primary key and foreign key). I wrote a script to do it: after 17 hours,
only 7600 child tables are created.

The script is still running, I can see that one child tables is created about every minute. The CPU
Usage is 100%. The query speed is really slow now (I set constraint_exclusion=on).

This stress test is for the partition plan I'm going to make, since we don't want to add another
Field just for partitioning. So is there something I did wrong? Or postgres cannot handle too many
Child tables? That way I need to come up with a new partition plan.

The system is 32-bit Linux, dual core, 4G memory. Postgres version is 8.1.21.

Thanks,
John