1.38. ddlscript_prepare( integer, integer )

    declare
    	p_set_id			alias for $1;
    	p_only_on_node		alias for $2;
    	v_set_origin		int4;
    begin
    	-- ----
    	-- Grab the central configuration lock
    	-- ----
    	lock table sl_config_lock;
    
    	-- ----
    	-- Check that the set exists and originates here
    	-- ----
    	select set_origin into v_set_origin
    			from sl_set
    			where set_id = p_set_id
    			for update;
    	if not found then
    		raise exception 'Slony-I: set % not found', p_set_id;
    	end if;
    	if v_set_origin <> getLocalNodeId('_schemadoc') then
    		raise exception 'Slony-I: set % does not originate on local node',
    				p_set_id;
    	end if;
    
    	-- ----
    	-- Create a SYNC event, run the script and generate the DDL_SCRIPT event
    	-- ----
    	perform createEvent('_schemadoc', 'SYNC', NULL);
    	return 1;
    end;