On P, 2005-04-24 at 04:00 +0300, Hannu Krosing wrote:
How much change would it be to have an option to not used LISTEN/NOTIFY
in slony ?

On heavily changing databases with some long-running transactions
pg_listener can easily grow  to tens of megabytes in size and this can
become the main bottlenect to slony's performance, as pg_listener is a
table with no indexes.

And even if there were indexes, sending notifications is un-needed
overhead for databases which have above certain amount of constant
traffic.

Of course this could be also done by slon's in a dynamic way, i.e when
getting heavy stream of sl_events, just UNSUBSCRIBE and after N queries
in a row getting nothing, do a SUBSCRIBE, similar to how gigabit
ethernet drivers for some cards work under linux, switching to polling
mode after a certain number of interrupts/sec is reached.

-- 
Hannu Krosing <hannu at tm.ee>