Re: Improving compressibility of WAL files

>>> Aidan Van Dyk <aidan@highrise.ca> 01/08/09 5:02 PM >>> 
> *I* would really like this wal zero'ing...
pg_clearxlogtail (in pgfoundry) does exactly the same zeroing of the
tail as a filter.  If you pipe through it on the way to gzip, there
is no increase in disk I/O over a straight gzip, and often an I/O
savings.  Benchmarks of the final version showed no measurable
performance cost, even with full WAL files.
It's not as convenient to use as what your patch does, but it's not
all that hard either.  There is also pglesslog, although we had
pg_clearxlogtail working before we found the other, so we've never
checked it out.  Perhaps it does even better.
-Kevin