3145073
Questão 1
Questão
What do the privileges associated with your role (the STUDENT role) allow you to do?
Responda
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Create tables
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Drop tables
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Create triggers
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All of the above
Questão 2
Questão
Foreign keys in the relational model make it possible to:
Responda
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Maintain entity integrity
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Create unique records
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Open the back door of the house when we have lost our primary key
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Create relationships between tables
Questão 3
Questão
A database may contain __________.
Responda
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tables.
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metadata.
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triggers.
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stored procedures.
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All of the above.
Questão 4
Questão
You need to create a column in a table that will store numbers in the form nnn.xx (e.g., 145.67) What data type is this?
Responda
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NUMBER(5)
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NUMBER(5,2)
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FLOAT(3,2)
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NUMBER(3,2)
Questão 5
Questão
The relational model __________.
Responda
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was first proposed in the late 1960's/early 1970's
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was developed by E.F Codd
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was developed at IBM
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resulted in the DBMS product, DB2
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All of the above.
Questão 6
Questão
What is the main difference between the Oracle SQL data types VARCHAR2 and CHAR?
Responda
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CHAR is variable in length
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CHAR allows for numbers and text
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VARCHAR2 is variable in length
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VARCHAR2 has a maximum length of 255 characters
Questão 7
Questão
Which of the following is NOT a property of a valid relation?
Responda
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All tuples must be unique – i.e., there must be an attribute or set of attributes that uniquely identifies each row
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Each attribute in a relation has a distinct name
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Attributes and tuples are not ordered
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Each relation must contain data
Questão 8
Questão
A null indicates:
Responda
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A numeric value with value 0
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The absence of a value
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A very small value
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An erroneous value
Questão 9
Questão
In the relational database terminology, a table is synonymous with:
Responda
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A relation
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A row
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An attribute
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A column
Questão 10
Questão
In the relational database terminology, a tuple is synonymous with:
Responda
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An attribute
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A column
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A relation
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A row
Questão 11
Questão
Data models have the following features:
Responda
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Structure, operators, constraints
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Entity integrity, referential integrity, domain integrity
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Relations, attributes, tuples
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Relational algebra, relational calculus, SQL
Questão 12
Questão
What SQL command would you execute in Oracle to show the structure of a table called Workshop?
Responda
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DESCRIBE Workshop;
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DEMONSTRATE Workshop;
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SELECT * FROM Workshop;
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SHOW Workshop;
Questão 13
Questão
An unknown value is indicated by:
Responda
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The string of characters "null"
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The null "value"
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The value 0
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The string of characters "TBA"
Questão 14
Questão
A relation that contains data recording Murdoch students' performance in units, has the following attributes:
(StudentNumber, StudentName, UnitCode, Year, Semester, Grade, Mark).
What would be an appropriate primary key for this relation?
Responda
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(StudentNumber)
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(StudentNumber, UnitCode, Grade)
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(StudentNumber, UnitCode, Year, Semester)
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(StudentNumber, StudentName, UnitCode, Year, Semester, Grade, Mark)
Questão 15
Questão
In the relational database terminology, an attribute is synonymous with:
Responda
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A relation
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A column
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A table
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A row
Questão 16
Questão
Which of the following statements does NOT apply to relational databases?
Responda
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Relational databases are simple to understand
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Relational databases have a strong mathematical foundation
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Relational databases have a strong procedural orientation
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Tables are one of the basic components of relational databases
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