3145073
Pregunta 1
Pregunta
What do the privileges associated with your role (the STUDENT role) allow you to do?
Respuesta
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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
Pregunta 2
Pregunta
Foreign keys in the relational model make it possible to:
Respuesta
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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
Pregunta 3
Pregunta
A database may contain __________.
Respuesta
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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.
Pregunta 4
Pregunta
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?
Respuesta
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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)
Pregunta 5
Pregunta
The relational model __________.
Respuesta
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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.
Pregunta 6
Pregunta
What is the main difference between the Oracle SQL data types VARCHAR2 and CHAR?
Respuesta
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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
Pregunta 7
Pregunta
Which of the following is NOT a property of a valid relation?
Respuesta
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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
Pregunta 8
Pregunta
A null indicates:
Respuesta
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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
Pregunta 9
Pregunta
In the relational database terminology, a table is synonymous with:
Respuesta
-
A relation
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A row
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An attribute
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A column
Pregunta 10
Pregunta
In the relational database terminology, a tuple is synonymous with:
Respuesta
-
An attribute
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A column
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A relation
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A row
Pregunta 11
Pregunta
Data models have the following features:
Respuesta
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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
Pregunta 12
Pregunta
What SQL command would you execute in Oracle to show the structure of a table called Workshop?
Respuesta
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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;
Pregunta 13
Pregunta
An unknown value is indicated by:
Respuesta
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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"
Pregunta 14
Pregunta
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?
Respuesta
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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)
Pregunta 15
Pregunta
In the relational database terminology, an attribute is synonymous with:
Respuesta
-
A relation
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A column
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A table
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A row
Pregunta 16
Pregunta
Which of the following statements does NOT apply to relational databases?
Respuesta
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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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