In previous releases it was possible to observe whether an automatic
checkpoint was in progress by looking to see if there was a postmaster
child process doing one. In 8.0 this will not work because the bgwriter
is always there. I am thinking that for tasks such as performance
debugging it would be a good idea if the bgwriter could emit postmaster
log messages at start and end of a checkpoint. However, this should
probably not happen at the default LOG level since it would clutter the
logs with perfectly routine messages. Any opinions about what elog
level to use for this?
regards, tom lane