disk space usage unexpected

Good day,

I have a PostgreSQL 8.4 database installed on WinXP x64 with very heavy
writing and updating on a partitioned table. Sometimes within one minute,
there are tens of file with size=1,048,576kb (such as
filenode.1,filenode.2,...filenode.43) created in the database subdirectory
within PGDATA/base.

This caused the disk space quickly used up. Is this expected?

Thanks for any information



Best Regards

Rose Zhou