when to checkpoint?

[Thomas Ledbetter <tledbett@revelstone.net>]

  So.. Ive been reading up hardcore on Berkeley database administration
regarding how to do archival and recovery, and its pretty cool stuff.

  Yet I have the following questions:
  
  Database archival will be done on one of our master servers, so its
not necessary to keep alot of old transaction logfiles on the replicas,
but in order to clean out them out, a periodic checkpoint is necessary. 

  Initially, I was thinking that we should do this once per day, off
hours, but would it make more sense to do this more frequently over the
course of the day to keep the checkpoint process less expensive per
iteration?  

  What kinds of metrics should be used to determine how frequently this
should be done?  


  Second, would there be that great of a performance gain when disabling
transaction logging altogether?  

  If I have two master servers keeping, say, a week's worth of
transaction logs, a sound archival process, and a backup LDIF, would it
make sense to just disable transaction logging altogether across the
replicas?


  Third, I now understand how to do archival and recovery using the
Berkeley tools, but is there a 'best practice' document out there
anywhere from someone who utilizes this method that I could take a look
at to make sure Im not missing anything?