Question 9: Query Processing Models . . . . . . . . . . . . . . . . . . . . . . . . . [10 points] Check True or False for each of the following statements. (a) [2 points] 2 T 2 F With the iterator processing model, each operator will immedi- ately emit a tuple to its parent as soon its child produces a tuple. (b) [2 points] 2 T 2 F With the materialization processing model, the DBMS pushes tuples up the query plan from one operator to the next. (c) [3 points] 2 T 2 F Index scans are slower in the iterator model (compared to the materialization and vectorization models) because the DBMS has to traverse the B+Tree from the root every time the scan operators parent calls next(). (d) [3 points] 2 T 2 F Regardless of what query processing model a DBMS uses, it will always store the intermediate results of each operator in the buffer pool in case they are larger than the amount of memory available to the system.

Question 9: Query Processing Models [10 points] Check 'T'rue or 'F'alse for each of the following statements. (a) [2 points] TF With the iterator processing model, each operator will immediately emit a tuple to its parent as soon its child produces a tuple. (b) [2 points] TF With the materialization processing model, the DBMS pushes tuples up the query plan from one operator to the next. (c) [3 points] TF Index scans are slower in the iterator model (compared to the materialization and vectorization models) because the DBMS has to traverse the B+Tree from the root every time the scan operator's parent calls next(). (d) [3 points] TF Regardless of what query processing model a DBMS uses, it will always store the intermediate results of each operator in the buffer pool in case they are larger than the amount of memory available to the system