1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
san4es73 [151]
3 years ago
6

Consider the following protocol for concurrency control. The database system assigns each transaction a unique and strictly incr

easingly id at the start of the transaction. For each data item, the database system also keeps the id of the last transaction that has modified the data item, called the transaction-id of the data item. Before a transaction T wants to read or write on a data item A, the database system checks whether the transaction-id of A is greater than the id of T . If this is the case, the database system allows T to read/write A. Otherwise, the database system aborts and restarts T.
Question1:

Does this protocol allow only a serializable schedule for transactions? If not, you may suggest a change to the protocol so that all schedules permitted by this protocol are serializable. You should justify your answer.

Question 2:

Propose a change to this protocol or the modified version you have designed for part (a) that increases its degree of concurrency, i.e., it allows more serializable schedules.
Computers and Technology
1 answer:
nasty-shy [4]3 years ago
4 0

Answer:

(a) yes, this protocol allows only serializable schedules for transactions as due to this the system maintains it's consistency. As in this protocol a unique transaction id is being assigned and with the help of that transaction id the system would be able to identify the process which has taken place in what particular order. For example, in case of bank transfers

balance = 1000 transaction id 100

write ADD 200 transaction id 101

write SUB 1100 transaction id 102

write ADD 900 transaction id 103

in here with the help of transaction id we can check which operation has happened in which order, if not then some operation will not happen like 102 immediately after 100 and skipping 101

(b) the modified version of this protocol would be to also consider the time of transaction and take this factor in the consideration

You might be interested in
What type of document is a mobile device's EULA?
MakcuM [25]
EULA stands for End User License Agreement. This document is the contract between the software application author or publisher and the user of that application. It is also called "software license", because it establishes the purchaser's right to use the software on the mobile device. T<span>he user agrees to pay for the privilege of using the software, and promises the software author or publisher to comply with all restrictions stated in the EULA. </span>
6 0
3 years ago
Now you are ready to implement a spell checker by using or quadratic. Given a document, your program should output all of the co
Harlamova29_29 [7]

Answer:

Sorry po idont know po ehhh sorry

5 0
2 years ago
1. Bluetooth
Elza [17]

Complete Question:

1. A wireless technology standard for exchanging data over short distances

2. A particular brand of mobile phone/PDA

3. A network that operates over a limited distance, usually for one or a few users

1. Bluetooth

2. PAN

3. Blackberry

Answer:

1. Bluetooth 2. Blackberry . 3. PAN

Explanation:

1. Bluetooth is a wireless technology standard, used in order to exchange data between mobile devices, like smartphones, tablets, headsets, wearables, over short distances in a one-to-one fashion (which means that it is not possible to build a network based in Bluetooth).

2. Blackberry is a brand of mobile phones/PDAs, very popular a decade ago, because it was the first one to allow mobile users to access e-mails and messages from anywhere, at any time.

3. PAN (Personal Area Network) is an ad-hoc network that it is only available for data exchange at a very short distance, within the reach of a person, i.e. a few meters as a maximum.

It is thought to allow someone to interact with his nearest environment (laptop, tablet, PDA) and it can be wireless (like Bluetooth) or wired (via USB cables).

4 0
3 years ago
Write out code for a nested if statement that allows a user to enter in a product name, store the product into a variable called
OlgaM077 [116]

Answer:

product_name = input("Enter product name : ")

if product_name=="pen"or"book"or"box"or"pencil"or"eraser":

   if product_name == "pen":  

       amount = 10

       print(f"Product Name: {product_name}\nCost: {amount} rupees")

   if product_name == "book":

       amount = 100

       print(f"Product Name: {product_name}\nCost: {amount} rupees")

   if product_name == "box":  

       amount = 150

       print(f"Product Name: {product_name}\nCost: {amount} rupees")

   if product_name == "pencil":  

       amount = 5

       print(f"Product Name: {product_name}\nCost: {amount} rupees")

   if product_name == "eraser":

       amount = 8

       print(f"Product Name: {product_name}\nCost: {amount} rupees")

else:  

   print("Item not found!")

Explanation:

The python program is a code of nested if-statements that compares the input string to five items of the first if-statement. For every item found, its code block is executed.

6 0
3 years ago
Write important of ICT in personal life?
mr Goodwill [35]

Answer:

ICT is a great impact for are daily lives. It can improve the quality of a human life. The reason why it can improve that, it’s because it can be used as a learning and education media, the mass communication media in promoting and campaigning practical and important issues, such as the health and social area.

Explanation:

4 0
3 years ago
Other questions:
  • A table with a width set to 600 pixels will look ________ on a monitor with resolution set to 640 × 480 than on a monitor with r
    10·1 answer
  • What folder holds 32-bit programs installed in a 64-bit installation of windows?
    12·1 answer
  • What answer best explains why improper netiquette is considered dangerous? Individuals who violate user policies are often charg
    14·2 answers
  • Catering question<br> What is the hottest food in the world
    5·1 answer
  • Why are answers not appearing? I've seen many complain about this recently.
    8·1 answer
  • How does a author develop a character in a story?
    14·2 answers
  • Life without internet points
    7·2 answers
  • I dont know how to put the negative sigh on my computer
    5·2 answers
  • All Office programs have similar commands on the tab for changing the document view a. File b. View c. Locate d. display ​
    5·1 answer
  • As a member of the help desk administration team, you've been assigned to update the driver for the network adapter that is inst
    15·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!