I've prepared a significantly simplified version of the patch. The two
main changes are
(a) it does not update the pg_stat_bgwriter anymore, it just prints an
info to the server log
(b) a new GUC is not required, it's driven by the log_checkpoints
This version will log at least 10 'checkpoint status' lines (at 10%, 20%,
30%, ...) and whenever 5 seconds since the last log elapses. The time is
not checked for each buffer but for 128 buffers.
So if the checkpoint is very slow, you'll get a message every 5 seconds,
if it's fast you'll get 10 messages.
Tomas
