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

Program using c++ only on visual studio pig is a simple two player dice game, played with one die. the first player to reach or surpass 50 is the winner. each player takes a turn rolling the dice. they add to the pot with each roll, having to decide to roll again and increase the pot, or cash out. the risk being they could lose the amount they’ve accumulated into the pot. the rules for each player’s die roll. 1. roll the dice. a. if user rolled a 1, i. the pot gets set to zero ii. the other player goes to step 1. b. a roll of 2-6 is added to the pot. 2. user can choose to hold or roll again. a. choice roll. return to step 1. b. choice hold. i. increment player score by the pot amount. ii. pot gets set to 0. iii. second player gets to roll and goes to step 1. program requirements: ● before each opponent begins ○ output the score for the person and the computer. ○ output the opponents whose turn is beginning and ask the user to hit enter to continue. ● with each dice roll. ○ output the die value, and amount of the round pot. ○ if it’s the users roll ask if they want to roll again ( r ) or hold ( h ). your program should allow r, r, h or h as valid input. if input is anything else, ask the user again until valid input is obtained. ○ the ai will continue playing until the round pot is 20 or more. ● once a player’s score is greater or equal to 50 then they have won, it will no longer ask if they want to keep rolling the die or not. ● once there is a winner ○ score totals are output along with who the winner was. user or computer ○ player is asked if they want to play again y or n. valid input should be y, y, or n, n. ● when a new game starts the starting roll goes to the player that did not roll last. if the user rolled last in the previous game, then the computer rolls first and vice versa. when the program first begins, the player will make the first roll of the first game. development notes : ● you will need a way to roll dice in your program. the rand() function works well, but returns an integer. if we want numbers 0 – 9 we can get the value modulus 10. ● call srand() with a value to seed it. it’s common to seed it with the current computer clock, include ctime, and then call srand(time(

Laire writes a letter to her grandmother, in which she describes an amusement park she visited last week. she adds pictures of that place in her letter. which feature of a word processing program will claire to remove unwanted parts of the pictures?

The program below has been generalized to read a user's input value for hourlywage. run the program. notice the user's input value of 10 is used. modify that input value, and run again. generalize the program to get user input values for workhoursperweek and workweeksperyear (change those variables' initializations to 0). run the program. monthsperyear will never change, so define that variable as final. use the standard for naming final variables. ex: final int max_length