Hello.

I read that Slony uses LISTEN/NOTIFY pgsql features to implement immediate
spreading of all the master changes to subsribers:
http://www.postgresql.org/docs/8.2/interactive/sql-notify.html
But seems information is spreaded not so quickly as I expect. E.g., when I
post something to the master, changes may appear on slave with 2-3 seconds
delay.

I could decrease sync_interval to 100 ms (for example) and it helps, BUT in
this case slon daemon from the slave begins to bomb the master with the
query:

select last_value from "_moikrug_cluster".sl_log_status
(10 queries per seconds).

It is not good for master's CPU to process such large number of queries (if
I have 10 slaves - 100 queries/s, aargh!).

So, the question is: how to make the Slony to update slaves as fast as
possible without bombing the master with periodical queries? And - what is
the detailed meaning of sync_interval?

P.S.
I tried to watch postgres logs and noticed that slave runs LISTEN/UNLISTEN
periodically, but the number of UNLISTEN is greater than the number of
LISTEN. So - maybe my configuration is simply broken, and slon does not
listen anything at all? Please say what debug information should I post
here.
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