} else if (op instanceof ProjectExpression && ((ProjectExpression)op).isProjectStar()) {
int inputNum = ((ProjectExpression)op).getInputNum();
LogicalRelationalOperator pred = (LogicalRelationalOperator)gen.getPlan().getPredecessors(gen).get(inputNum);
if (pred.getSchema() == null) {
throw new SchemaNotDefinedException("Schema for " + pred.getName() + " is not defined.");
}
for(LogicalFieldSchema f: pred.getSchema().getFields()) {
if (f.uid == uid) {
input.add(uid);
found = true;
}
}
} else if (gen.getFlattenFlags()[i]) {
// if uid equal to the expression, get all uids of original projections
List<Operator> ss = exp.getSinks();
for(Operator s: ss) {
if (s instanceof ProjectExpression) {
int inputNum = ((ProjectExpression)s).getInputNum();
LogicalRelationalOperator pred = (LogicalRelationalOperator)gen.getPlan().getPredecessors(gen).get(inputNum);
if (pred.getSchema() == null) {
throw new SchemaNotDefinedException("Schema for " + pred.getName() + " is not defined.");
}
if (pred.getSchema().findField(uid) != -1) {
input.add(uid);
found = true;
}
}
}
}
if (found) {
break;
}
}
if (!found) {
throw new IOException("uid " + uid +" is not in the schema of LOForEach");
}
}
// for the flatten bag, we need to make sure at least one field is in the input
for(int i=0; i<ll.size(); i++) {
if (!gen.getFlattenFlags()[i]) {
continue;
}
LogicalExpressionPlan exp = ll.get(i);
Operator s = exp.getSinks().get(0);
if (s instanceof ProjectExpression) {
int inputNum = ((ProjectExpression)s).getInputNum();
int colNum = ((ProjectExpression)s).getColNum();
LogicalRelationalOperator pred = (LogicalRelationalOperator)gen.getPlan().getPredecessors(gen).get(inputNum);
LogicalSchema predSchema = pred.getSchema();
if (predSchema == null) {
throw new SchemaNotDefinedException("Schema for " + pred.getName() + " is not defined.");
}
if (predSchema.getField(colNum).type == DataType.BAG) {
long fuid = predSchema.getField(colNum).uid;
LogicalSchema fschema = predSchema.getField(colNum).schema;