public static List<Datum[]> execQuery(Map<String, Schema.TableFromFile> tables, PlanNode q)
throws SqlException {
switch (q.struct) {
case LEAF:
switch (q.type) {
case SCAN:
ScanNode node = (ScanNode) q;
ScanOperator sop = new ScanOperator(node);
return sop.getTuples(tables);
// break;
case NULLSOURCE:
NullSourceNode nNode = (NullSourceNode) q;
return new ArrayList<Datum[]>();
// break;
}
break;
case UNARY:
switch (q.type) {
case AGGREGATE:
AggregateNode aggrNode = (AggregateNode) q;
List<Datum[]> aggrResult = execQuery(tables, aggrNode.getChild());
AggregateOperator aop = new AggregateOperator(aggrNode, aggrResult);
return aop.getTuples();
// break;
case SELECT:
SelectionNode selectNode = (SelectionNode) q;
List<Datum[]> selectResult = execQuery(tables, selectNode.getChild());
SelectOperation slop = new SelectOperation(selectNode);
return slop.getTuples(selectResult, selectNode.getCondition());
// break;
case PROJECT:
ProjectionNode projNode = (ProjectionNode) q;
List<Datum[]> projResult = execQuery(tables, projNode.getChild());
ProjectOperation prop = new ProjectOperation(projNode);
ExprTree e = null;
return prop.getTuples(projResult, e);
// break;
}
break;
case BINARY:
switch (q.type) {
case JOIN:
JoinNode joinNode = (JoinNode) q;
JoinOperator jop = new JoinOperator(joinNode);
List<Datum[]> lResult = execQuery(tables, joinNode.getLHS());
List<Datum[]> rResult = execQuery(tables, joinNode.getRHS());
return jop.getTuples(lResult, rResult);
// break;
case UNION:
UnionNode unionNode = (UnionNode) q;
UnionOperator uop = new UnionOperator(unionNode);
List<Datum[]> lUResult = execQuery(tables, unionNode.getLHS());
List<Datum[]> rUResult = execQuery(tables, unionNode.getRHS());
return uop.getTuples(lUResult, rUResult);
// break;
default:
break;
}
}
throw new SqlException("execQuery() is unimplemented");
}