| Slony-I 2.2.10 Documentation | ||||
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Function Properties
Language: PLPGSQL
Return Type: bigint
subscribeSet (sub_set, sub_provider, sub_receiver, sub_forward, omit_copy) Makes sure that the receiver is not the provider, then stores the subscription, and publishes the SUBSCRIBE_SET event to other nodes. If omit_copy is true, then no data copy will be done.declare
v_set_origin int4;
v_ev_seqno int8;
v_ev_seqno2 int8;
v_rec record;
begin
-- ----
-- Grab the central configuration lock
-- ----
lock table sl_config_lock;
--
-- Check that the receiver exists
--
if not exists (select no_id from sl_node where no_id=
p_sub_receiver) then
raise exception 'Slony-I: subscribeSet() receiver % does not exist' , p_sub_receiver;
end if;
--
-- Check that the provider exists
--
if not exists (select no_id from sl_node where no_id=
p_sub_provider) then
raise exception 'Slony-I: subscribeSet() provider % does not exist' , p_sub_provider;
end if;
-- ----
-- Check that the origin and provider of the set are remote
-- ----
select set_origin into v_set_origin
from sl_set
where set_id = p_sub_set;
if not found then
raise exception 'Slony-I: subscribeSet(): set % not found', p_sub_set;
end if;
if v_set_origin = p_sub_receiver then
raise exception
'Slony-I: subscribeSet(): set origin and receiver cannot be identical';
end if;
if p_sub_receiver = p_sub_provider then
raise exception
'Slony-I: subscribeSet(): set provider and receiver cannot be identical';
end if;
-- ----
-- Check that this is called on the origin node
-- ----
if v_set_origin != getLocalNodeId('_schemadoc') then
raise exception 'Slony-I: subscribeSet() must be called on origin';
end if;
-- ---
-- Verify that the provider is either the origin or an active subscriber
-- Bug report #1362
-- ---
if v_set_origin <> p_sub_provider then
if not exists (select 1 from sl_subscribe
where sub_set = p_sub_set and
sub_receiver = p_sub_provider and
sub_forward and sub_active) then
raise exception 'Slony-I: subscribeSet(): provider % is not an active forwarding node for replication set %', p_sub_provider, p_sub_set;
end if;
end if;
-- ---
-- Enforce that all sets from one origin are subscribed
-- using the same data provider per receiver.
-- ----
if not exists (select 1 from sl_subscribe
where sub_set = p_sub_set and sub_receiver = p_sub_receiver) then
--
-- New subscription - error out if we have any other subscription
-- from that origin with a different data provider.
--
for v_rec in select sub_provider from sl_subscribe
join sl_set on set_id = sub_set
where set_origin = v_set_origin and sub_receiver = p_sub_receiver
loop
if v_rec.sub_provider <> p_sub_provider then
raise exception 'Slony-I: subscribeSet(): wrong provider % - existing subscription from origin % users provider %',
p_sub_provider, v_set_origin, v_rec.sub_provider;
end if;
end loop;
else
--
-- Existing subscription - in case the data provider changes and
-- there are other subscriptions, warn here. subscribeSet_int()
-- will currently change the data provider for those sets as well.
--
for v_rec in select set_id, sub_provider from sl_subscribe
join sl_set on set_id = sub_set
where set_origin = v_set_origin and sub_receiver = p_sub_receiver
and set_id <> p_sub_set
loop
if v_rec.sub_provider <> p_sub_provider then
raise exception 'Slony-I: subscribeSet(): also data provider for set % use resubscribe instead',
v_rec.set_id;
end if;
end loop;
end if;
-- ----
-- Create the SUBSCRIBE_SET event
-- ----
v_ev_seqno := createEvent('_schemadoc', 'SUBSCRIBE_SET',
p_sub_set::text, p_sub_provider::text, p_sub_receiver::text,
case p_sub_forward when true then 't' else 'f' end,
case p_omit_copy when true then 't' else 'f' end
);
-- ----
-- Call the internal procedure to store the subscription
-- ----
v_ev_seqno2:=subscribeSet_int(p_sub_set, p_sub_provider,
p_sub_receiver, p_sub_forward, p_omit_copy);
if v_ev_seqno2 is not null then
v_ev_seqno:=v_ev_seqno2;
end if;
return v_ev_seqno;
end;