Transcript CSCI 242 Advanced Database

Introduction
» How the course works
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Homework
Project
Exams
Grades
» prerequisite
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CSCI 6441: Mandatory prerequisite
Take the prereq or get permission to take the course
» Goals of the course
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Advanced topics
Topics that are often not understood
Realistic experience
» Workload
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Heavy workload from the beginning
Workload gets much heavier when project starts
» Relational Principles
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Why relational, why it matters
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» Weekly assignments
» Assignments intended to be challenging and to
make an important point
» Assignments to be submitted by email to
[email protected]
» No attachments
» Assignments due at the start of class
» Late assignments are not accepted
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» One project will involve the entire class
» Work will be performed in functional teams
» Every student must produce programs, will be
graded on personally produced results
» You will need to program using MySQL, PHP,
and JavaScript; if you don’t know them start
learning
» You need to already have programming skills to
complete this course
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» The project will be a questionnaire generator
and evaluator of results
» One team will build the questionnaire builder
and administrator
» Another team will build the data analysis
» Both will be built as WordPress plugins
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» At the end of the project, each student will
have access to all code written by the project
» Any student (and myself) are free to do
anything desired with the project code
» You will receive an email asking you to agree to
these stipulations
» If you have a problem with this approach,
please speak up after class tonight
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Midterm and final
Midterm will be closed book, in class
Midterm date will not change
Plan your schedule now:
˃ Be here for the midterm, no makeup exams
˃ Be here for the final, no makeup exams
» Midterm will test your ability to work with
concepts discussed in lecture and covered by
homework
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» A: Good quality graduate work, only minor
issues with correctness
» B: Acceptable graduate work, one or more
major issues
» C: Not acceptable graduate work, several
serious issues
» F: Does not show basic understanding
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» CSCI 6441 is a mandatory prerequisite
» Take it before this course
» If you think you know the material, you need to
explain it and get permission
» First assignment is intended to clear this up
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» Misunderstood topics
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Normalization
Database design
Performance
SQL
» Advanced topics
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Time in databases
Translucency
Performance
» Realistic experience
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Realistic team size
Accountability
Emerging requirements
» Current Developments
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Big data
NOSQL
Cloud Computing
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» This course is for advanced students who want
to learn a lot and want to work hard
» If you’re not in a position to work hard, want to
“slide by,” you are in the wrong course
» If you don’t know how to program, don’t want
to learn PHP, MySQL and Flex (on your own),
this is not the course for you
» But if you do want to be the database guru on a
project at work, then stay in this course!
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» Earlier database systems: hierarchies, networks
as data models
˃ Relationships represented as physical connections
˃ Structure of relationship imbedded in applications
» Relational: independent table as data model
˃ Relationships represented by equal values
˃ Structure of relationships invisible to applications
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» Relational Database: a set of relations
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» Relation: a set of ordered pairs
» Ordered pair: a pair of values, such that
interchanging the two values changes the
meaning
˃ That is, <a,b>=<b,a> iff a=b and b=a
» Specifying a relation by enumeration:
R={<a,b>,<c,d>,<e,f>}
˃ This is a relation consisting of three ordered pairs.
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» Ordered pairs can model more than two values
through nesting:
˃ <a, b, c> == <<a,b>, c>
˃ <a, b, c, d> == <<a,b>, c, d>
˃ And so on
» This extends the ordered pair so that it can
model a tuple of any length
» Now a relation starts to look like our notion of a
file, with each tuple corresponding to our
notion of a record
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» Relation is a set of ordered pairs (modeling a
set of tuples), so:
» 1. exchanging order of values within a tuple
changes the meaning of the tuple
» 2. exchanging the order of tuples within a
relation does not change the meaning of the
tuple
» 3. duplicate tuples are not allowed
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» Now we build a database as a collection of
independent relations, each describing
instances of a single entity type
» For example:
˃ Employee (employee#, job, salary, department)
˃ Department (department#, departmentname, location)
(this is called schema notation)
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» We need a way to insert data into the database,
retrieve data from the database, and changes
values that are stored in the database
» We define a data language that can be used
from any programming language to do that
» The data language (SQL) has a lot of power and
can save a lot of programming work if you
understand it
» You’ll have a brief chance to learn more about
SQL in this course
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» Database courses talk about normalization
» Students usually don’t learn more than
memorizing definitions
» We will talk about Roberts’s Rules, plain English
rules that give you a highly normalized database
» Then we will talk about the normalization rules
and what they mean in English
» You will have the chance to really understand
how to do this
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» Time in databases is a complex issue
» There’s the time something happened and the
time it’s entered into the database
» And there’s also the effective time, which may
differ from those two times
» And there’s the need to capture a history of
previous values and roll back to it
» We’ll examine all of these cases of time
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» Typically the GRANT statement is used to give
access to a database
» A DBA enters the statement, and a user has
access
» But that’s not good enough if there may be
thousands of people on the Web using a
database
» We’ll study translucency, a way to provide
access control without GRANT statement
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» Professional standards, like the work
environment, will be followed:
˃ Arrive at class on time
˃ Submit homework on time
˃ Limit answers to 50 words
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A class Web site has been established
Everything about the class is on it
Please read it
When changes are made to the site a note will
be sent to the class email list
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» A class email list has been established
» If you got the email sent today, then you’re on it
» You can follow instructions on the Web site to
enroll a different email address
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