1.60. enablesubscription_int( integer, integer, integer )

Function Properties

Language: PLPGSQL

Return Type: integer

enableSubscription_int (sub_set, sub_provider, sub_receiver) Internal function to enable subscription of node sub_receiver to set sub_set via node sub_provider. slon does most of the work; all we need do here is to remember that it happened. The function updates sl_subscribe, indicating that the subscription has become active.

declare
	p_sub_set			alias for $1;
	p_sub_provider		alias for $2;
	p_sub_receiver		alias for $3;
	v_n					int4;
begin
	-- ----
	-- Grab the central configuration lock
	-- ----
	lock table sl_config_lock;

	-- ----
	-- The real work is done in the replication engine. All
	-- we have to do here is remembering that it happened.
	-- ----

	-- ----
	-- Well, not only ... we might be missing an important event here
	-- ----
	if not exists (select true from sl_path
			where pa_server = p_sub_provider
			and pa_client = p_sub_receiver)
	then
		insert into sl_path
				(pa_server, pa_client, pa_conninfo, pa_connretry)
				values 
				(p_sub_provider, p_sub_receiver, 
				'<event pending>', 10);
	end if;

	update sl_subscribe
			set sub_active = 't'
			where sub_set = p_sub_set
			and sub_receiver = p_sub_receiver;
	get diagnostics v_n = row_count;
	if v_n = 0 then
		insert into sl_subscribe
				(sub_set, sub_provider, sub_receiver,
				sub_forward, sub_active)
				values
				(p_sub_set, p_sub_provider, p_sub_receiver,
				false, true);
	end if;

	-- Rewrite sl_listen table
	perform RebuildListenEntries();

	return p_sub_set;
end;