Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

OS Concepts (Ozbirn) > Chapter 12 (File Management) > Flashcards

Chapter 12 (File Management) Flashcards

1
Q

What are some desirable properties of files?

A

Long-term existence

Shareable between processes

Structure

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What operation allows a process to perform functions on a file?

A

Open

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What is a field?

A

Basic element of data containing a single value

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

T/F A field can only be fixed length

A

F, fixed or variable length

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What is a record?

A

Collection of related fields treated as a unit

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

T/F A record cannot be variable length

A

F, it can

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What is a file?

A

Collection of similar records treated as a single entity

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What is a database?

A

Collection of related data (1 or more files)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What are the criteria for choosing a file organization?

A

Rapid access

Ease of update

Economy of storage

Simple maintenance

Reliability

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

List the five fundamental file organizations

A

Pile

Sequential file

Indexed sequential file

Indexed file

Direct or hashed file

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

How does pile collect data?

A

In the order it arrives

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

How is data accessed in pile?

A

Exhaustive search

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What is the purpose of pile?

A

Accumulate a mass of data and save it

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Which file organization may be useful to store data prior to processing it?

A

Pile

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

T/F In a sequential file, some fields are different

A

F, all are the same

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What are the attributes of a sequential file?

A

Field names and lengths

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Where are new records placed for a sequential file?

A

Log file or transaction file

18
Q

Where is a sequential file useful?

A

Batch processing

19
Q

How can additions be handled in an indexed sequential file?

A

Overflow file

20
Q

What’s special about an indexed sequential file?

A

Reduces time to access a single record while still providing sequential processing

21
Q

What’s the difference between a partial and exhaustive index?

A

Partial index only has pointers to records having the field of interest. Exhaustive index has pointers to every record

22
Q

When are direct or hash file mostly useful?

A

If records are only accessed one at a time

23
Q

How are indexes often implemented?

A

B-trees

24
Q

What’s the primary benefit of the B-tree for indexes?

A

Fewer disk accesses

25
Q

What is a directory?

A

A file owned by the OS and managed by the file management system

26
Q

What information does a directory contain?

A

Attributes, location, and ownership

27
Q

What are some directory operations?

A

Search

Create file

Delete file

List directory

Update directory

28
Q

T/F Every level of a directory structure may contain files and subdirectories

A

T

29
Q

What are two issues with file sharing?

A

Access rights

Simultaneous access

30
Q

What are the typical classes for access rights?

A

Specific user

Group of users

All

31
Q

What are some examples of access rights?

A

None

Knowledge

Execution

Reading

Appending

Updating

Changing protection

Deletion

32
Q

What are two approaches for simultaneous access?

A

Lock the file when it is to be updated

Lock individual records during update

33
Q

When is a blocking of records performed?

A

When writing data

34
Q

List three blocking methods

A

Fixed

Variable-length spanned

Variable-length unspanned

35
Q

What are the properties of the variable-length spanned blocking method?

A

Variable-length records which may span blocks

Unlimited record size

May require multiple I/O’s

36
Q

What are the properties of the variable-length unspanned blocking method?

A

Variable-length records which do not span blocks

May cause internal fragmentation

37
Q

What does a file consist of?

A

Collection of blocks

38
Q

What are two management issues for secondary storage management?

A

Allocating blocks to files

Maintaining a list of free blocks

39
Q

What are some file allocation issues?

A

Whether to allocate the maximum space required all at once, or to allocate space in portions

If portions are used, how big should a portion be?

If portions are used, how to keep track of the portions?

40
Q

What are some techniques for free space management?

A

Bit tables

Chained free portions

Indexing

Free block list

OS Concepts (Ozbirn) (12 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions