1.24. cleanupevent( )

Function Properties

Language: PLPGSQL

Return Type: integer

cleaning old data out of sl_confirm, sl_event. Removes all but the last sl_confirm row per (origin,receiver), and then removes all events that are confirmed by all nodes in the whole cluster up to the last SYNC.

declare
	v_max_row	record;
	v_min_row	record;
	v_max_sync	int8;
begin
	-- ----
	-- First remove all but the oldest confirm row per origin,receiver pair
	-- ----
	delete from sl_confirm
				where con_origin not in (select no_id from sl_node);
	delete from sl_confirm
				where con_received not in (select no_id from sl_node);
	-- ----
	-- Next remove all but the oldest confirm row per origin,receiver pair.
	-- Ignore confirmations that are younger than 10 minutes. We currently
	-- have an not confirmed suspicion that a possibly lost transaction due
	-- to a server crash might have been visible to another session, and
	-- that this led to log data that is needed again got removed.
	-- ----
	for v_max_row in select con_origin, con_received, max(con_seqno) as con_seqno
				from sl_confirm
				where con_timestamp < (CURRENT_TIMESTAMP - '10 min'::interval)
				group by con_origin, con_received
	loop
		delete from sl_confirm
				where con_origin = v_max_row.con_origin
				and con_received = v_max_row.con_received
				and con_seqno < v_max_row.con_seqno;
	end loop;

	-- ----
	-- Then remove all events that are confirmed by all nodes in the
	-- whole cluster up to the last SYNC
	-- ----
	for v_min_row in select con_origin, min(con_seqno) as con_seqno
				from sl_confirm
				group by con_origin
	loop
		select coalesce(max(ev_seqno), 0) into v_max_sync
				from sl_event
				where ev_origin = v_min_row.con_origin
				and ev_seqno <= v_min_row.con_seqno
				and ev_type = 'SYNC';
		if v_max_sync > 0 then
			delete from sl_event
					where ev_origin = v_min_row.con_origin
					and ev_seqno < v_max_sync;
		end if;
	end loop;

	-- ----
	-- If cluster has only one node, then remove all events up to
	-- the last SYNC - Bug #1538
        -- http://gborg.postgresql.org/project/slony1/bugs/bugupdate.php?1538
	-- ----

	select * into v_min_row from sl_node where
			no_id <> getLocalNodeId('_schemadoc') limit 1;
	if not found then
		select ev_origin, ev_seqno into v_min_row from sl_event
		where ev_origin = getLocalNodeId('_schemadoc')
		order by ev_origin desc, ev_seqno desc limit 1;
		raise notice 'Slony-I: cleanupEvent(): Single node - deleting events < %', v_min_row.ev_seqno;
			delete from sl_event
			where
				ev_origin = v_min_row.ev_origin and
				ev_seqno < v_min_row.ev_seqno;

        end if;

	-- ----
	-- Also remove stale entries from the nodelock table.
	-- ----
	perform cleanupNodelock();

	return 0;
end;