AND WELL IDENTIFIED ANSWERS [ALREADY
GRADED A+] REAL EXAM 100%
A salesperson is authorized to sell 12 products; a product can be sold by 10
salespersons.
Which kind of binary relationship is described in this example? - ANS✔✔---
Many-to-many
Which three kinds of rules for referential integrity are provided by modern
relational database management systems? - ANS✔✔---Insert, Delete,
Update
What is an important aspect of "referential integrity"? - ANS✔✔---Reference
to data in one relation is based on values in another relation.
Sales data, detailing the customer names, products sold, and salespersons,
is kept in a database.
,Which kind of data in this database would qualify as intersection data related
to both the product and salesperson entities? - ANS✔✔---Customer names
What is an attribute or group of attributes that uniquely identify a tuple in a
relation? - ANS✔✔---Primary key
What is necessary for a primary key in one relation of a database to match
with its corresponding foreign key in another relation of the same database?
- ANS✔✔---A domain of values
What uniquely identifies each entity in a collection of entities but is not the
primary key? - ANS✔✔---The alternate key
What is a term for a set of columns in a table that can uniquely identify any
record in that table without referring to other data? - ANS✔✔---Candidate
key
What happens to the original data in database indexing? - ANS✔✔---It is
copied to the index.
Why are indexes created in a physical database design? - ANS✔✔---To
retrieve data directly using a pointer.
Why is an index created on a database column? - ANS✔✔---To optimize data
retrievals
Refer to the given SQL statement.
, SELECT SPNUM, SPNAME
FROM SALESPERSON
What is the correct line to add to the end of this statement to find
salespersons with a commission percentage of 15? - ANS✔✔---WHERE
COMMPERCT=15;
Refer to the given SQL statement.
SELECT COMMPERCT, YEARHIRE
FROM SALESPERSON
WHERE SPNUM=22;
How should this statement be altered to retrieve the entire record instead of
the commission percentage and year of hire? - ANS✔✔---Replace
COMMPERCT, YEARHIRE with an asterisk
What is a broad definition of data? - ANS✔✔---Raw facts that are captured
on printed or digital media
What are data? - ANS✔✔---Facts that are collected and stored in a database
system
What is a determining characteristic of unstructured data? - ANS✔✔---It
does not follow a data model.
Which is true about flat files? - ANS✔✔---They contain no internal
hierarchical organization.
Which technology has no internal hierarchy? - ANS✔✔---Flat files