We are now packaging RC2. If nothing comes up after RC2 is released, we
can move to final release.
The open items list is attached. The doc changes can be easily
completed before final. The only code issue left is with bgwriter. We
always knew we needed to find better defaults for its parameters, but we
are only now finding more fundamental issues.
I think the summary I have seen recently pegs it right --- our use of %
of dirty buffers requires a scan of the entire buffer cache, and the
current delay of bgwriter is too high, but we can't lower it because the
buffer cache scan will become too expensive if done too frequently.
I think the ideal solution would be to remove bgwriter_percent or change
it to be a percentage of all buffers, not just dirty buffers, so we
don't have to scan the entire list. If we set the new value to 10% with
a delay of 1 second, and the bgwriter remembers the place it stopped
scanning the buffer cache, you will clean out the buffer cache
completely every 10 seconds.
Right now it seems no one can find proper values. We were clear that
this was an issue but it is bad news that we are only addressing it
during RC.
The 8.1 solution is to have some feedback system so writes by individual
backends cause the bgwriter to work more frequently.
The big question is what to do during RC2? Do we just leave it as
suboptimal knowing we will revisit it in 8.1 or try an incremental
solution for 8.0 that might work better.
We have to decide now.
---------------------------------------------------------------------------
PostgreSQL 8.0 Open Items =========================
Current version at http://candle.pha.pa.us/cgi-bin/pgopenitems.
Changes
-------
* change bgwriter buffer scan behavior?
* adjust bgwriter defaults
Documentation
-------------
* synchonize supported encodings and docs
* improve external interfaces documentation section
* manual pages
Fixed Since Last Beta
---------------------
-- Bruce Momjian | http://candle.pha.pa.us pgman@candle.pha.pa.us | (610)
359-1001+ If your life is a hard drive, | 13 Roberts Road + Christ can be your backup. | Newtown Square,
Pennsylvania19073
