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WorksheetsPRELIM EXAM FOR INFORMATION MANAGEMENT
Total questions: 20
Worksheet time: 20mins
What is the correct definition/description of a database?
It is a structure that can store information about multiple types of entities, the attributes of those entities, and the relationships between the entities.
It is a computer counterpart to an ordinary paper file you might keep in a file cabinet, an accounting ledger, or other place.
It is a named column of multiple entities with domain association.
Data storage and retrieval can be done using the following four operations on the file except:
Read
Insert
Delete
Append
It is the set of allowable values for one or more attributes.
(a)
Degree of a relation is the number of tuples it contains.
True
False
Based on this Representative Table, identify/specify its attributes. Please use commas to separate values or variables.
(a)
In a relational algebra, produces a relation that contains only those tuples of R that satisfies the specified predicate.
Selection
Projection
Union
Produces a relation that contains all the tuples of R or S or both the R and S, duplicate tuples being eliminated. R and S must be union compatible.
Intersection
Union
Cartesian Product
Looking at a content of a record without changing it.
Read
Write
Update
The candidate key that is selected to identify tuples uniquely within the relation.
(a)
An attribute or set of attributes that uniquely identifies individual occurrences of an entity type.
(a)
If a tuple is a row, a column is an .
Relations
Attribute
Relationships
What will happen if DATA redundancy occur in a database?
Data integration is enforced.
There is data harmonization.
Data is in safe mode.
Data inconsistency will result.
The word fact derives from the Latin word facum which indicate findings derived through a process of evaluation, including review of testimony, direct observation, or otherwise.
True
False
He is the central authority in charge of Database.
Database Administrator
Application programmers
Operations Personnel
Based on the attached image, what is the name of the relation?
(a)
Study the attached image of a table. Provide its degree and cardinality. Use comma to separate values.
(a)
The following are disadvantages of database processing except:
Bulk file size
decreased redundancy
increased complexity
It is a line connecting the entities. It is simply an association between entities.
(a)
Given this relational algebraic expression, what does this usually mean?
σ course = "BSIT" (STUDENTS)
Selects tuples from STUDENTS where course = ‘BSIT’.
It extracts attributes whose course = ‘BSIT’.
It will not execute since course is not part of STUDENTS table.
Please specify what attributes are projected in this relational algebraic expression:
Π RepNum, LastName (Rep)
(a)
