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c. There is a frequent need to quickly retrieve cruise
data based on departure date.
d. Data about passengers from California must be
accessed quickly and much more frequently than
data about passengers from anywhere else.
e. There is a frequent need to quickly retrieve a list of
the port managers of the ports at which the ship on
any particular cruise will stop.
f. There is a frequent need to quickly find the total
number of passengers who were on any particular
cruise.
g. There is a frequent need to find the start and end
dates of cruises as quickly as possible.
h. There is a frequent need to find cruise data based on
ship
name
. Hint: The Ship Name attribute is unique.
4.
Consider the following relational database for the Super
Baseball League. It keeps track of teams in the league,
coaches and players on the teams, work experience of
the coaches, bats belonging to each team, and which
players have played on which teams. Note the following
facts about this environment:
• The database keeps track of the history of all the
teams that each player has played on and all the
players who have played on each team.
• The database keeps track of only the current team
that a coach works for.
• Team number, team name, and player number are
each unique attributes across the league.
•
Coach name is unique only within a team (and we
assume that a team cannot have two coaches of the
same name).
• Serial number (for bats) is unique only within a team.
•
In the Affiliation table, the years attribute indicates
the number of years that a player played on a team;
the batting average is for the years that a player
played on a team.
COACH Table
Team
Coach
Coach
−−−−−
Number
Name
Telephone
−−−−−−−
WORK EXPERIENCE Table
Team
Coach
Experience
Years Of
−−−−−
−−−−−
Number
Name
Type
Experience
−−−−−−−
−−−−−
BATS Table
Team
Serial
−−−−−
Number
Number
Manufacturer
−−−−−−−
PLAYER Table
Player
Player
Number
Name
Age
AFFILIATION Table
Player
Team
Batting
−−−−−
−−−−−
Number
Number
Years
Average
−−−−−−−
−−−−−−−
Analyze each of the following situations and, using
the physical database design techniques discussed in
this chapter, state how you would modify the logical
design shown to improve performance or otherwise
accommodate it.
a. There is a frequent need to quickly find the total
number of years that any particular player has played
in the league (i.e., the total number of years played
for all of the teams a player played for).
TEAM Table
Team
Team
Number
Name
City
Manager
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