/* We will simply create a scan operator for every relation in the query. */ void construct_scan_operators() { scan_operators = new Vector<ScanOperator>(); for (BaseRelationSchema rs : query_relations) { /* There may be predicates involving just that relation. */ Vector<Predicate> v = new Vector<Predicate>(); for (Predicate p : query_predicates) if (p.isScanPredicate(rs)) v.add(p); scan_operators.add(new ScanOperator(rs, v)); } }