Wal logs continued...

Earlier I posted with my problems about the WAL logs eating up all my
diskspace.  I tried the solutions offered--checkpoint after a big copy and
shortening the time between flushes.  They helped somewhat.

Unfortunately, the problem snow seems to happen when I vacuum-analyze after a
big delete.  Even if the vacuum takes more than 2 minutes (the amount of time
between flushes that I set in postgresql.conf), the logs continue to grow.
Currently the vacuum has been running for about 20 minutes after a delete of
about 2,000,000 records out of 5,000,000, and the WAL logs are at about 1.5 G.

Versions: RH 6.2, PG 7.1.1

Is there some way to set the number of log files before a flush/checkpoint
thing?  We are going to go to a bigger machine next week, but this is quite
an inconvenience, and it would probably benefit the DB as a whole to place
some limit on the size of the WAL.

I would code it myself, but I can't yet (next year, after I finish a couple
of Stevens' books....).  If there is any thing else I can do to help, please
let me know.

Thanks,
W