HashMap<String, Long> aliasToKnownSize = new HashMap<String, Long>();
aliasToKnownSize.put("alias1", 1024l);
aliasToKnownSize.put("alias2", 2048l);
aliasToKnownSize.put("alias3", 4096l);
DDLTask task1 = new DDLTask();
task1.setId("alias2");
DDLTask task2 = new DDLTask();
task2.setId("alias3");
// joins alias1, alias2, alias3 (alias1 was not eligible for big pos)
HashMap<Task<? extends Serializable>, Set<String>> taskToAliases =
new HashMap<Task<? extends Serializable>, Set<String>>();
taskToAliases.put(task1, new HashSet<String>(Arrays.asList("alias2")));