Computers and Technology, 10.03.2020 19:42 hschuman01osrzvf
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.
Answers: 2
Computers and Technology, 21.06.2019 17:20
The liang book has an example called which is a javafx application that reads the javabook database using a preparedstatement object. using it as a guide, create a similar application called findbooks. it will read a list of authors from the bookdb created in problem 1 and display them in a listview. if the user selects an author, it should display the author's book titles in a textarea.
Answers: 2
Computers and Technology, 22.06.2019 12:00
Which of the following does 3d animation create an illusion of on the screen? a. depth b. emotion c. length d. dialogue
Answers: 1
Computers and Technology, 22.06.2019 18:40
Mariah was working on a multimedia presentation that included both video and audio files. the file was huge, and she wanted to send it to her coworker in another office. she needed to reduce the size of the file so that it could be transmitted faster. the utility she used to do this was
Answers: 2
Computers and Technology, 23.06.2019 14:00
Technician a says that with self-adjusting clutch systems, the release bearing constantly rotates. technician b says that the ball bearing portion of the release bearing should be lubricated with high-temperature grease during routine maintenance. which technician is correct?
Answers: 2
Consider the following protocol for concurrency control. The database system assigns each transactio...
Mathematics, 23.07.2020 20:01
History, 23.07.2020 20:01
Engineering, 23.07.2020 20:01