ws a record used for recording information about a named event.
Which of the following statement is incorrect? (2 Points)
VAR r: record
event:array[1..10] of char;
place:array[1..20] of record
plname:array[1..15] of char;
date: array[1..5] of record
mo:1..12;
day:1..31;
year:integer
end
end
end;
A)This is a one-dimensional array of records,also called a table.
B)This is so called record of arrays;
C)The event can occur in up to 20 places and on up to 5 different dates in each place.
D)A reference to r.place[i].date[j].mo will access the month of the jth occurrence,
in the ith place,of the event named in r.event.
(68)Which of the following statements is true regarding simple sort techniques? (2 Points)
A)Exchange sort is frequently referred to as a bubble sort.
B)Exchange sort is the least expensive
C)If random data are in an array that is to be sorted,an Insertion Sort will give the
best performance for large elements with small sort items.
D)Both Insertion Sort and Selection Sort require O(n)moves.
(69) Which UNIX command creates a symbolic link named myfile in the current directory to
the file/etc/hosts?
A) In -s /etc/hosts myfile B) In -s myfile /etc/hosts
C) link -s /etc/hosts myfile D) link -s myfile /etc/hosts
(70)Which MS-DOS command is correct?
A) DEL /s *.bat B) DEL *.exe/sp
C) DEL *.obj >nul: D) DEL *.com *.sys
(71)A virtual memory system has five virtual pages numbered zero through four and
three page frames. All the page frames are initially empty. How many page faults
are generated with the following access sequence using a FIFO replacement policy?
(2 Points)
0 1 2 3 0 1 5 0 1 2 3 4
A) 8 B) 9 C) 10 D) 11
(72)Which element is NOT part of a microkernel? (2 Points)
A) basic I/O B) a file system
C) IPC mechanisms D) memory management
(73)Which is local to a thread instead of a process? (2 Points)
A) a stack B) an open file C) a semaphores D) an address space
(74)What is a subselect statement?
A)a select statement that selects a subset of fields in a table
B)a select statement that returns a subset of the data in a table
C)a select statement that appears within another select statement
D)a select statement that returns a subset of the constraints on a field
(75)In developing a hospital database,it is determined that on the average,each patient
will have 6 treatments during a hospital stay. The averge length of a stay is three
days.The hospital has 1000 beds.There are on the average 800 patients occupying
beds each day.The relationship between PATIENT and TREATMENT is l:M.The relationship
between PATIENT and BED is 1: 1,conditional. If treatment record occurrences are
archived as soon as a patient is discharded from the hospital, how many occurrences
of the TREATMENT records will be stored in the TREATMENT database file on the
average? (2 Points)
A) 6,000 B) 4,800 C) 18,000 D)1,600
(76)Which of the following conditions will make a relation that is in first normal form
to be in second normal form?
Ⅰ.every non-key attribute is functionally dependent on the full set of primary key
attributes.
Ⅱ.no non-key attributes exist in the relation.
Ⅲ.the primary key consists of only one attribute.
A) Ⅰ only B) Ⅰand Ⅱ only C) Ⅰand Ⅲ only D) any of them
(77)The most commonly used locking level in implementing concurrency control is at which
of the following levels?
A) database B) table C) record D)field
(78)Which function is NOT served by building a prototype?
A) It takes the place of the final system.
B) It assists in gathering software requirements
C) It assists in estimating the cost of the project.
D) It is used as the foundation of the larger projects.
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