Estimating Database Disk Space

Hi All,

I'm running postgres.7.1.3-7

I'm concerned at the steady growth of disk space taken up by my
postgres.
I have three databases, each of which take up about 2+ MB when dumped.
I have tried deleting one database and re-installing. This suggests that
about 38Mb of disk space is taken up by each database. I suspect that if
postgres were deleted entirely, about 250 MB would be freed.

The FAQ suggests that about 7MB might be taken up by one database when
copied from a file into postgres. Other posts suggest that xlog might
add a further 20MB as an overhead. Indexes are mentioned elsewhere, but
without any means of estimating what their size should be.

Do the above figures seem sensible? Is the required disk space likely
to grow in proportion to the data, or is there an overhead of about
60MB of disk space needed to run each database?

TIA

Richard A Lough