Description
Introduction
The objective of this assignment is to learn how to implement index structures on data stored in the external memories.
What you must do
Assume that we have a relation Employee(id, name, bio, manager-id). The values of id and manager-id are integers each with the fixed
size of 8 bytes. The values of name and bio are character strings and take at most 200 and 500 bytes, respectively. Note that as opposed to
the values of id and manager-id, the sizes of the values of name and bio are not fixed and are between 1 to 200 (500) bytes. The size of
each page (block) is 4096 bytes (4KB). The size of each record is less than the size of a page. Using the provided skeleton code with this
assignment, write a C++ program that creates a dense and unclustered B+tree index file for relation Employee using attribute id. Your
program must also enable users to search the created index by providing the id of a record.
• Your program must first read an input Employee relation and build a B+tree index for the relation using attribute id. The input relation is
stored in a CSV file, i.e., each tuple is in a separate line and fields of each record are separated by commas. Your program must assume that
the input CSV file is in the current working directory, i.e., the one from which your program is running, and its name is Employee.csv. We
have included an input CSV file with this assignment as a sample test case for your program. Your program must create and search B+tree
indexes correctly for other CSV files with the same fields as the sample file.
• You may create a B+tree index by reading the input file and repeatedly inserting the input records in the data file and its relevant information
in the index file. To do this, you may use the fragments of the the program you have developed in the previous assignment to read input
records and store them in the data file. The data file is a heap (unsorted) file of variable-length records and pages on the external storage.
They are also explained in Sections 9.7.2 and 9.6.2 of Cow Book, respectively.
6/1/23, 1:03 AM Homework: B+tree Index (w5)
https://canvas.oregonstate.edu/courses/1939345/assignments/9237570?module_item_id=23191654 2/4
• Your program must insert the information about ids of the input records in the B+tree index file. The program mustdo this both while
creating the data file. It must store the B+tree index in a file with the name EmployeeIndex on the current working directory. Each node of
the B+tree is a record in this file. The structure of these records must follow the structure of B+tree nodes explained in the lecture. You may
treat these records as both fixed-length records and use the data structure described in the class to store fixed-length records and their
corresponding pages to store them in the index file. The pointer in the root and internal nodes keep addresses of referred nodes in the B+tree
index file. The pointers in the leaf nodes of the index must keep the addresses of their corresponding records on the created data file.
• During the index creation, your program may keep up to three pages plus the root of the index in main memory at any time. The submitted
solutions that use more main memory will not get any points.
• You must set the degree (d) of the index to 4.
• After finishing the index creation, your program should accept an Employee id in its command line and search the index file for all records of the
given id.
Like index creation, your program may use up to three pages plus the root of the index in main memory at any time. The submitted solutions that
use more main memory
will not get any points for implementing lookup operation. The user of your program may search for records of multiple ids, one id at a time.
• Each student has an account on hadoop-master.engr.oregonstate.edu server, which is a Linux machine. Your should ensure that your program
can be compiled and run on this machine.
You can use the following bash command to connect to it:
> ssh your_onid_username@hadoop-master.engr.oregonstate.edu
Then it asks for your ONID password and probably one another question. To access this server, you must be on campus or connect to the Oregon
State VPN.
• You can use following commands to compile and run C++ code:
> g++ -std=c++11 main.cpp -o main.out
> main.out
6/1/23, 1:03 AM Homework: B+tree Index (w5)
https://canvas.oregonstate.edu/courses/1939345/assignments/9237570?module_item_id=23191654 3/4
B+ Tree Index
Necessary files
Input file:Employee-2.csv (https://canvas.oregonstate.edu/courses/1939345/files/99023162?wrap=1)
(https://canvas.oregonstate.edu/courses/1939345/files/99023162/download?download_frd=1)
Following files contain the skeleton code to generate the required EmployeeIndex & DataFile. You may make changes to these files adhering to the
assignment requirements.
main.cpp (https://canvas.oregonstate.edu/courses/1939345/files/99069298?wrap=1)
(https://canvas.oregonstate.edu/courses/1939345/files/99069298/download?download_frd=1)
classes.h (https://canvas.oregonstate.edu/courses/1939345/files/99069300?wrap=1)
(https://canvas.oregonstate.edu/courses/1939345/files/99069300/download?download_frd=1)
What to turn in
The assignment is to be turned in before Midnight (by 11:59pm) on May 10. You may turn in the source code of your program through Canvas.
The assignment may be done in groups of two students. Each group may submit only one file that contains the full name, OSU email, and ONID of
every member of the group.
Grading criteria
The programs that implement the correct algorithm, return correct answers, and do not use more than allowed buffers will get the perfect score.
The ones that use more buffer than allowed will not get any points. The ones that implement the right algorithm but return partially correct answers
will get partial scores.
6/1/23, 1:03 AM Homework: B+tree Index (w5)
https://canvas.oregonstate.edu/courses/1939345/assignments/9237570?module_item_id=23191654 4/4
Total Points: 9
Criteria Ratings Pts
9 pts
Description
of criterion
9 pts
Full
Marks
7 pts
Minor Error
Lookup did not
return all the IDs
we were
searching for.
4.5 pts
Partial Credit
EmployeeIndex created
properly but Lookup
implementation did not match
assignment requirement.
3 pts
Major Error
Your program do not return any queries correctly.
Your EmployeeIndex file structure shows that you
are reading the EmployeeIndex file sequentially for
Lookup. It defeats the purpose of having a B+ tree
structure.
0 pts
No Marks
You did not meet
the assignment
requirements
