Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

CS 564 > Final Vocabulary > Flashcards

Final Vocabulary Flashcards

1
Q

row store

A

store next to each other
- traditional way
- disk -> files -> pages -> records

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

unordered heap files

A

records in no order

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

pid

A

page id
- the pages in a file

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

rid

A

record id
- the records on a page
- <page id, slot number>

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

storage hierarchy

A

primary storage, secondary storage, tertiary storage

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

primary storage

A

main memory (RAM) for currently used data

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

secondary storage

A

disk for the main database

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

tertiary storage

A

tapes for archiving older versions of the data

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

disk blocks

A

the unit data is stored and retrieved in

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

platter

A

circular hard surface on which data is stored by inducing magnetic changes

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

spindle

A

axis responsible for rotating platters

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

disk head

A

mechanism to read or write data

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

disk arm

A

moves to position a head on a desired track of the platter

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

track

A

circular path on surface of disk

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

block size

A

unit of read or write (aka page)

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

sectors

A

a part of the track

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

access time equation

A

rotational delay + seek time + transfer time

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

rotational delay

A

block under head

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

seek time

A

move head to right radius

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

transfer time

A

read time

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

buffer manager

A

responsible for bringing pages from disk to main memory as needed

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

buffer replacement policies

A

LRU, clock

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

sequential flooding

A

situation caused by LRU policy and repeated sequential scans

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

heap file as linked list

A

header page with one path for full pages and another path for pages with free space

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
heap fie as page directory
each entry for a page keeps track of page availability and number of free bytes
26
index
a data structure that organized records of a table to speed up retrieval
27
search key
attribute or combination of attributes used to retrieve the records (the filter)
28
index entries
two forms - contains record and key - contains key and pointer to record
29
primary index
if search key contains primary key
30
secondary index
if search key contains any other key
31
unique index
if search key contains a candidate key
32
composite search index
search on a combination of attributes - order matters!!
33
clustered index
the order of record matches order of index entries
34
unclustered index
unordered records - increases I/Os
35
parameters to consider when creating index
- access time (equality, range) - time to access, insert, delete - space
36
hash index
collection of buckets where each bucket contains one or more index entries
37
bucket
primary page + overflow pages
38
static hashing
fixed number of buckets
39
problems with static hashing
- cannot grow for more space - potentially wasted space if there are long overflow chains
40
extendible hashing
- dynamic hashing - keeps a directory of pointers to buckets - on overflow, directory is reorganized by doubling the size of it
41
duplicate keys
many index entries with same key value
42
Solving for duplicate keys
1. all entries with a given key are on a single page or overflow page 2. allow duplicate keys in data entries and modify search operation
43
bitmap index
store values in multiple tables - good for duplication and low cardinality
44
bitslice index
store value in binary into a single table - good for high cardinality
45
run
a subfile that is sorted
46
pass
each time two runs are merged
47
ACID properties
- atomicity - consistency - isolation - durability
48
transactions
a collection of operations that create a single atomic logical unit
49
atomicity
all actions in the TXN happen, or none happen - either commit or abort
50
consistency
a database in a consistent state will remain in a consistent state after the TXN
51
isolation
the execution of one TXN is isolated from other (possibly interleaved) TXNs - if T1, T2 are interleaved, the result should be the same as T1 then T2 or T2 then T1
52
durability
once a TXN commits, its effects must persist - have to write to disk
53
log
a list of modifications - keeps track of what TXNs change - stores new and old values of TXNs - only keeps track of writes
54
Write-Ahead Logging (WAL)
1. force log record for an update to disk before page goes to disk (atomicity) 2. write to disk all log records for a TXN before commit (durability)
55
serial schedule
no interleaving
56
serializable schedule
a interleaved schedule that is equivalent to some serial schedule
57
serializable schedule
an interleaved schedule that is equivalent to some serial schedule
58
equivalent schedule
when two schedules will have the same effect for every database state
59
conflict
when two different TXMs access the same variable and one of the TXNs is a write
60
anomalies
instances where isolation and/or consistency is broken because of a bad schedule
61
types of anomalies
- dirty read - unrepeatable read - overwriting uncommitted data
62
dirty read
when a TXN reads modified data not yet commited - occurs because of a write, read conflict
63
dirty read
when a TXN reads modified data not yet committed - occurs because of a write, read conflict
64
unrepeatable read
when data is read twice but in between the reads, the data was modified - occurs because of a read, write conflict
65
overwriting uncommitted data
when a TXN overwrites the data of an uncommitted TXN - occurs because of a write, write conflict
66
conflict equivalent
when two schedules have the same actions of the same TXNs and conflicting actions are ordered in the same way
67
conflict serializable
when a schedule is conflict equivalent to a serial schedule
68
locking
used for concurrency control
69
shared mode (S lock)
when a TXN wants to read, and another transaction also wants to read
70
exclusive mode (X lock)
no other TXN can read or write
71
Strict 2 Phase Locking
Lock procedure that maintains isolation and consistency - each TXN must obtain an S lock before reading and a X lock before writing - if there is an X lock, no other TXN can get a lock - all locks are released when TXN completes
72
Deadlock
when all transactions are waiting for a lock to be released

CS 564 (2 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions