| Slony-I 2.0.3_RC2 Documentation | ||||
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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;