6.130. unsubscribeset(integer, integer)

Function Properties

Language: PLPGSQL

Return Type: bigint

unsubscribeSet (sub_set, sub_receiver) Unsubscribe node sub_receiver from subscription set sub_set. This is invoked on the receiver node. It verifies that this does not break any chains (e.g. - where sub_receiver is a provider for another node), then restores tables, drops Slony-specific keys, drops table entries for the set, drops the subscription, and generates an UNSUBSCRIBE_SET node to publish that the node is being dropped.

declare
	p_sub_set			alias for $1;
	p_sub_receiver		alias for $2;
	v_tab_row			record;
begin
	-- ----
	-- Grab the central configuration lock
	-- ----
	lock table sl_config_lock;

	-- ----
	-- Check that this is called on the receiver node
	-- ----
	if p_sub_receiver != getLocalNodeId('_schemadoc') then
		raise exception 'Slony-I: unsubscribeSet() must be called on receiver';
	end if;

	-- ----
	-- Check that this does not break any chains
	-- ----
	if exists (select true from sl_subscribe
			where sub_set = p_sub_set
				and sub_provider = p_sub_receiver)
	then
		raise exception 'Slony-I: Cannot unsubscribe set % while being provider',
				p_sub_set;
	end if;

	-- ----
	-- Remove the replication triggers.
	-- ----
	for v_tab_row in select tab_id from sl_table
			where tab_set = p_sub_set
			order by tab_id
	loop
		perform alterTableDropTriggers(v_tab_row.tab_id);
	end loop;

	-- ----
	-- Remove the setsync status. This will also cause the
	-- worker thread to ignore the set and stop replicating
	-- right now.
	-- ----
	delete from sl_setsync
			where ssy_setid = p_sub_set;

	-- ----
	-- Remove all sl_table and sl_sequence entries for this set.
	-- Should we ever subscribe again, the initial data
	-- copy process will create new ones.
	-- ----
	delete from sl_table
			where tab_set = p_sub_set;
	delete from sl_sequence
			where seq_set = p_sub_set;

	-- ----
	-- Call the internal procedure to drop the subscription
	-- ----
	perform unsubscribeSet_int(p_sub_set, p_sub_receiver);

	-- Rewrite sl_listen table
	perform RebuildListenEntries();

	-- ----
	-- Create the UNSUBSCRIBE_SET event
	-- ----
	return  createEvent('_schemadoc', 'UNSUBSCRIBE_SET', 
			p_sub_set::text, p_sub_receiver::text);
end;