NFO20003 数据库

Database Systems INFO20003 A2 S1 2023 Page 1 of 7
INFO20003 Semester 1, 2023

Assignment 2: SQL
Due: 6:00pm Friday, 28 April 2023
Weighting: 10% of your total assessment

Research Papers Database
Description
You and a group of fellow undergrads have created a start-up like Google Scholar called ‘newScholar’.
newScholar is a free accessible web search engine that provides a broad range of information on
scholarly publications. It also provides information on researchers and relations among scholarly
publications and researchers.
For each researcher, newScholar records the researcher’s details such as first name, last name, and
one email address. Each researcher can also be associated with a few keywords representing their
‘research area’, such as Databases, Machine learning, Psychology, Medicine, etc. For each researcher,
newScholar maintains their list of publications. The researchers who author a publication together are
called ‘co-authors’.
For each publication, newScholar stores its title, date of publication, start page number (e.g., 475), end
page number (e.g., 500), and a list of authors (there can be multiple authors of a publication, where
each author is a researcher). Each publication can also be associated with a few keywords representing
its ‘research area’, such as Databases, Machine learning, Psychology, Medicine, etc. NewScholar
database will not store the actual publications, but rather a link to the document objects. Each publication
is linked to one document object. For each document object, newScholar stores the URL link and the
document size in KB. Each publication has a list of references (i.e., it “cites” other publications), where
each reference is another publication. If publication A is in the reference list of another publication B,
then A is “cited by” B. Figure 1 shows an example publication with its basic information and its list of
references.
NewScholar manually curates a list of top 10 publications every fortnight depending on the number of
citations of the publications. A publication can make it to top 10 more than once over time. For each
paper that is in the top 10 for a particular fortnight at a particular position, newScholar keeps a record of
the start date when a publication reached that position (beginning of the fortnight) and end date (end of
the fortnight). If a publication is again in the next fortnight’s top 10 (whether in the same position, or
different), a new row is recorded, with the start/end dates being the start/end dates of this new fortnight.
For example, the publication entitled “Learning to index” can be number 1 for the fortnight from January
1st - January 14th, 2022 but the rank drops to number 3 from January 15th - January 28th, 2022. This
would result in 2x rows, one with position 1 and one with position 3. Note that we do not need to know
the rationale why this is the current ranking.
Database Systems INFO20003 A2 S1 2023 Page 2 of 7

Fig 1: An example of publication with title, authors, and the list of references

The Data Model

Fig 2: The physical ER model of newScholar startup database.

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Assignment 2 Setup
A dataset is provided which you can use when developing your solutions. To set up the dataset,
download the file newScholar_2023.sql from the Assignment link on Canvas and run it in Workbench.
This script creates the database tables and populates them with data. Note that this dataset is provided
for you to experiment with: but it is not the same dataset as what your queries will be tested against (the
schema will stay the same, but the data itself may be different). This means when designing your queries
you must consider edge cases even if they are not represented in this particular data set.
The script is designed to run against your account on the Engineering IT server
(info20003db.eng.unimelb.edu.au). If you want to install the schema on your own MySQL Server
installation, uncomment the lines at the beginning of the script.

Note: Do NOT disable only_full_group_by mode when completing this assignment. This mode is
the default, and is turned on in all default installs of MySQL workbench. You can check whether it is
turned on using the command “SELECT @@sql_mode;”. The command should return a string
containing “ONLY_FULL_GROUP_BY” or “ANSI”. When testing, our test server WILL have this mode
turned on, and if your query fails due to this, you will lose marks.

The SQL tasks
In this section are listed 10 questions for you to answer. Write one (single) SQL statement per question.
Subqueries and nesting are allowed within a single SQL statement – however, you may be penalized
for writing overly complicated SQL statements.
DO NOT USE VIEWS (or ‘WITH’ statements/common table expressions) to answer questions.

Some clarifications:
1. If publication A has 5 citations, that means publication A has been cited by 5 other publications
(i.e., it does not mean that publication A cited 5 other publications).
2. A researcher’s total number of citations refers to the count of citations of all the publications
they’ve authored. If a publication has multiple citations, all the citations count towards the total
count. For instance, if a researcher has 3 publications; the first one is cited 2 times, the second
one 3 times, and the third one 5 times, we say that the researcher’s total number of citations is
10.

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Questions:
1. List all publications with no references (i.e., find publications that do not cite any other
publications). Your query should return results of the form (publicationID, title). (1 mark)
2. Find the most recent publication. Assume there are no ties (only one publication is the most
recent). Your query should return results of the form (publicationID, title, dateOfPublication). (1
mark)
3. List all papers from the author “Renata Borovica-Gajic” that are at least 10 pages in length. Your
query should return results of the form (publicationID, title). (1 mark)
4. Find the publication with the highest number of citations. Note that, if a publication A is in the
reference list of publication B and publication C, then the number of citations of A is 2. If there
are ties, then you must return all publications with the highest number of citations. Your query
should return results of the form (publicationID, title, citationCount), with one row per publication
in case of a tie. (2 marks)
5. List the URLs of the papers that have ‘Databases’ as one of their research areas and have been
cited at least once. Your query should return results of the form (publicationID, documentUrl). (2
marks)
6. Find the researchers who have at least 2 citations overall, and who have had publications in the
top ten list at least once. Your query should return results of the form (firstName, lastName). (2
marks)
7. Find which research area has had the highest number of publications in the top-ten publication
list over time. If a publication has appeared in the top 10 several times, count such publications
just once in the calculation. If there are ties, then you must return all results. Your query should
return results of the form (keywordID, word), with one row per research area in case of a tie. (2
marks)
8. List the researcher with the highest total citations. If there are ties, then you must return all such
results. Your query should return results of the form (firstName, lastName, totalCitationCount),
with one row per researcher in case of a tie. (3 marks)
9. Find the researchers in ‘Databases’ research area who have co-authored at least one publication
with at least one researcher from ‘Machine learning’ research area (regardless of the research
area of the publication itself). Note that we only want to consider co-authorships where the
‘Databases’ researcher is distinct from the ‘Machine Learning’ researcher: if there is a
‘Databases’ researcher who also is in the ‘Machine learning’ area, they must have co-authored
with a different researcher who is in the ‘Machine learning’ area to be included. Your query should
return results of the form (firstName, lastName). (3 marks)
10. Find the researchers who have not co-authored a publication on or after 01/01/2023 (where
01/01/2023 is the date of the publication) with the researcher named “Renata Borovica-Gajic”
but have had at least one publication before that date co-authored with “Renata Borovica-Gajic”
(that means they have had joint publications in the past, but not on or after 01/01/2023). Your
query should return results of the form (firstName, lastName) for all such researchers. (3 marks)

Database Systems INFO20003 A2 S1 2023 Page 5 of 7
SQL Response Formatting Requirements
To help us mark your assignment queries as quickly/accurately as possible, please ensure that:
Your query returns the projected attributes in the same order as given in the question, and
does not include additional columns. E.g., if the question asks ‘return as (userId, name)’,
please write “SELECT userId, name …” instead of “SELECT name, userId…” (you
can name the columns using `AS` however you’d like, only the order matters).
Please do NOT use “databaseName.tableName” format. E.g., please write “SELECT userId
FROM users…” instead of “SELECT userId FROM coltonc.users …”.
Ensure that you are using single quotes( ‘ ) for strings (e.g. …WHERE name = ‘bob’…)and
double quotes ( “ ) only for table names (e.g. SELECT name FROM “some table name
with spaces”…). Do NOT use double quotes for strings “…WHERE name = “bob”…”.

Submission Instructions
Your submission will be in the form of an SQL script. There is a template file on the LMS, into which you
will paste your solutions and fill in your student details (more information below).
This .sql file should be submitted on Canvas by 6pm on the due date of Friday, 28 April 2023. Name
your submission as 987654.sql, where 987654 corresponds to YOUR student id.

Filling in the template file:
The template file on the LMS has spaces for you to fill in your student details and your answers to the
questions. There is also an example prefilled script available on the LMS as well. Below are screenshots
from those two documents explaining the steps you need to take to submit your solutions:
Step Example
1. At the top of the template,
you’ll need to replace
“XXXXXXXX” with your
student number and name
Template

Example Filled in

2. For each question 1-10,
place your SQL solution in
between the “BEGIN QX”
and “END QX” markers.
Ensure each query is
Template

Database Systems INFO20003 A2 S1 2023 Page 6 of 7
terminated with a
semicolon “;”
Example Filled in

3. Test that your script is
valid SQL by running it from
MySQL Workbench. Run the
entire script by copy-pasting
this entire file into a new
workbench tab, placing your
cursor at the start of the file
(without selecting anything),
and pressing the lightning
bolt to run the entire file.

All queries should run
successfully one after
another. If not, check to
make sure you added
semicolons ‘;’ after each
query.
All 10 queries ran sequentially and were successful.

Late submission
Unless you have an approved extension (see below), you will be penalised -10% of the total number of
marks in the assignment per day that your submission is late. For instance, if you received a 78% raw
score, but submitted 2 days late, you'd receive a 58% score for the assignment.

Database Systems INFO20003 A2 S1 2023 Page 7 of 7
Requesting a Submission Deadline Extension
If you need an extension due to a valid (medical) reason, you will need to provide evidence to support
your request by 5pm on Thursday 27 April. Extensions received after this time may be rejected.
Medical certificates need to be at least two days in length.
To request an extension:
Email Timothy Hermanto ([email protected]) from your university email address,
supplying your student ID, the extension length that you require and supporting evidence. Please
add INFO20003 in the subject title. ? If your submission deadline extension is granted you will receive an email reply granting the new
submission date. Do not lose this email! ?

Reminder: INFO20003 Hurdle Requirements
To pass INFO20003, you must pass two hurdles:
Hurdle 1: Obtain at least 50% (15/30) for the three assignments (each worth 10%) ?
Hurdle 2: Obtain at least 50% (35/70) for the combination of the quizzes and final exam ?
Therefore, it is our recommendation that you attempt every assignment and question in the exam.

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