Slony-I 2.2.11 Documentation
Prev | Fast Backward | Chapter 8. Schema schemadoc | Fast Forward | Next

# 8.128. subscribeset_int(p_omit_copy integer, p_sub_forward integer, p_sub_receiver integer, p_sub_provider boolean, p_sub_set boolean)

Function Properties

Language: PLPGSQL

Return Type: integer

subscribeSet_int (sub_set, sub_provider, sub_receiver, sub_forward, omit_copy) Internal actions for subscribing receiver sub_receiver to subscription set sub_set.

    declare
    	v_set_origin		int4;
    	v_sub_row			record;
    	v_seq_id			bigint;
    begin
    	-- ----
    	-- Grab the central configuration lock
    	-- ----
    	lock table sl_config_lock;

    	-- ----
    	-- Lookup the set origin
    	-- ----
    	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_int(): set % not found', p_sub_set;
    	end if;

    	-- ----
    	-- Provider change is only allowed for active sets
    	-- ----
    	if p_sub_receiver = getLocalNodeId('_schemadoc') then
    		select sub_active into v_sub_row from sl_subscribe
    				where sub_set = p_sub_set
    				and sub_receiver = p_sub_receiver;
    		if found then
    			if not v_sub_row.sub_active then
    				raise exception 'Slony-I: subscribeSet_int(): set % is not active, cannot change provider',
    						p_sub_set;
    			end if;
    		end if;
    	end if;

    	-- ----
    	-- Try to change provider and/or forward for an existing subscription
    	-- ----
    	update sl_subscribe
    			set sub_provider = p_sub_provider,
    				sub_forward = p_sub_forward
    			where sub_set = p_sub_set
    			and sub_receiver = p_sub_receiver;
    	if found then

    		-- ----
    		-- This is changing a subscriptoin. Make sure all sets from
    		-- this origin are subscribed using the same data provider.
    		-- For this we first check that the requested data provider
    		-- is subscribed to all the sets, the receiver is subscribed to.
    		-- ----
    		for v_sub_row in select set_id from sl_set
    				join sl_subscribe on set_id = sub_set
    				where set_origin = v_set_origin
    				and sub_receiver = p_sub_receiver
    				and sub_set <> p_sub_set
    		loop
    			if not exists (select 1 from sl_subscribe
    					where sub_set = v_sub_row.set_id
    					and sub_receiver = p_sub_provider
    					and sub_active and sub_forward)
    				and not exists (select 1 from sl_set
    					where set_id = v_sub_row.set_id
    					and set_origin = p_sub_provider)
    			then
    				raise exception 'Slony-I: subscribeSet_int(): node % is not a forwarding subscriber for set %',
    						p_sub_provider, v_sub_row.set_id;
    			end if;

    			-- ----
    			-- New data provider offers this set as well, change that
    			-- subscription too.
    			-- ----
    			update sl_subscribe
    					set sub_provider = p_sub_provider
    					where sub_set = v_sub_row.set_id
    					and sub_receiver = p_sub_receiver;
    		end loop;

    		-- ----
    		-- Rewrite sl_listen table
    		-- ----
    		perform RebuildListenEntries();

    		return p_sub_set;
    	end if;

    	-- ----
    	-- Not found, insert a new one
    	-- ----
    	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;
    	insert into sl_subscribe
    			(sub_set, sub_provider, sub_receiver, sub_forward, sub_active)
    			values (p_sub_set, p_sub_provider, p_sub_receiver,
    				p_sub_forward, false);

    	-- ----
    	-- If the set origin is here, then enable the subscription
    	-- ----
    	if v_set_origin = getLocalNodeId('_schemadoc') then
    		select createEvent('_schemadoc', 'ENABLE_SUBSCRIPTION',
    				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
    				) into v_seq_id;
    		perform enableSubscription(p_sub_set,
    				p_sub_provider, p_sub_receiver);
    	end if;

    	-- ----
    	-- Rewrite sl_listen table
    	-- ----
    	perform RebuildListenEntries();

    	return p_sub_set;
    end;

Prev | Home | Next
subscribeset(p_omit_copy integer, p_sub_forward integer, p_sub_receiver integer, p_sub_provider boolean, p_sub_set boolean) | Up | tablestovacuum()