The following table presents the lock requests by transactions T1, T2, T3, and T4. S(.) and X(.) stand for 'shared lock' and exclusive lock', respectively. To prevent deadlocks, use a lock manager that uses the Wait-Die policy. Assume the four transactions have priority: T1< T2

The following table presents the lock requests by transactions T1, T2, T3, and T4. S(.) and X(.) stand for 'shared lock' and exclusive lock', respectively. To prevent deadlocks, use a lock manager that uses the Wait-Die policy. Assume the four transactions have priority: T1< T2

Database System Concepts

7th Edition

ISBN:9780078022159

Author:Abraham Silberschatz Professor, Henry F. Korth, S. Sudarshan

Publisher:Abraham Silberschatz Professor, Henry F. Korth, S. Sudarshan

Chapter1: Introduction

Section: Chapter Questions

Problem 1PE

See similar textbooks

Similar questions

1. The Database contains 4 transactions. Find the association rules exact from these set using Apriori, assume the minimum support is 60% and minimum confidence is 80% Transaction ID Item Bought 001 K, A, D, B 002 D, A, C, E, B 003 C, A, B, E 004 B, A, D a) Make Tabular Binary Representation b) Find Frequent item set using Support For 1-item set For 2-item set For 3-item set c) Extract rules and calculate their confidence
Consider the following database Scherpa for Car Ownership Database. In the database, we store information about cars and their owners. A car is owned by one owner, but an owner mayown many cars. Car (No, model, year, OwnerlD) Owner (ID, CPR, Name, address,Tel) Write SQL statements to: 1. List ID and name of all customers living in 'Bahrain'. 2. Delete all cars records from Car with unknown owner.
q8- Choose ALL that apply.
4. SQL Rose Chantik is a cosmetic company that has many branches in Malaysia. The company must manage many product bookings by agents. An agent is attached to a branch and each branch must have a manager. Every agent may have a supervisor to monitor their progress in the company. The supervisor is aiso an agent. Agents may book multiple types of product through the system. However, an agent can only book not more than 100 quantities for each product on the same day. The relational schemes for booking system are as follows: BRANCH AGENT BOOKING BOOK_PRODUCT PRODŪCT (BRID, BRNAME, BRADDRESS, BRMANAGERNO) (AGID, AGNAME, AGPHONE, AGEMAIL, BRID, SUPERVISORID) (BOOKID, BOOKDATE, BOOKADDRESS, BOOKPRICE, AGID) (BOOKID, PRODID, QUANTITY) (PRODID, PRODNAME, PRODPRICE, PRODEXPIRY) Note: The primary keys are underlined. a) By using SQL, modify the BRANCH table columns with following criteria: b) Insert this following data into BRANCH table. Table 2.0: Branch Table Data BRANCH ADDRESS NO 30, JALAN…
please help me to solve this simple operation question of paython 7. s='a,b,c', s2=('x','y','z'), s3=':'s.split(','): s3.join('abc'): s3.join(s2)
Q. In given its own version of the database a. Snapshot b. None of the above isolation each transaction is
Suppose the deferred modification technique is used in a database. a. Is the old-value part of an update log record required any more? Why or why not? b. If old values are not stored in update log records, transaction undo. Is clearly not feasible. How would the redo-phase of recovery have to be modified as a result? C. Deferred modification can be implemented by keeping updated data items in local memory of transactions, and reading data items that have not been updated directly from the database buffer. Suggest how to efficiently implement a data item read, ensuring that a trans action sees its own updates.
Alternative Assignment 2 Task: Create a protected user account database.using PHP and SQL Detail: Create a protected user account database where is security identify a user is allow them to access to the system (Home page), based on the following requirements: You suppose to implement secure registration form using regular expression and proper validation, login page with username and password-based authenticated using the following mandatory: Must allow the creation, deletion of user accounts Must provide a demonstration application that grants user access when provide a valid username/password pair The passwords must be protected. No administrator who has access to the underlying file system should be able to see clear text passwords (cryptographic hashing). The password file itself should be protected from tampering Reject any attempts to provide invalid data. Each user account required a validation Password must be protected using cryptography hashing such as md5, sha1,…
The university contains many academic departments in a college, such as the Department of Computer Engineering, Software Engineering, and English Language Teaching etc. And a variety of courses are offered by each department. And possibly an instructor can teach more than one course. For example, a physics professor can teach math's also. You need to create a database schema for this application. Notice that the database users are varied corresponding to their privileges and interest. Assuming that you have DBA, end users etc. create database schema using any RDBMS (mysql, and postgresql are preferred). Insert few record as related to your courses and department. Notice that you need to show ER-Diagram, in the latest step. Note: you should include the .sql file and ERdiagram.jpeg and in your uploaded file / folder to the LMS, also the .sql file shall contains the inserted data to the relations
B- Practical Open WEKA > Explorer open "vote.arff " database select "mx-missile" attribute Then complete the following: (1) Number of instances in the database = . (2) Number of attributes =. (3) Number of missing values = . (4) Data type is . (5) Number of distinct values ............ (6) Name of the 14th attribute of the database = ................
Select from below ALL statements that are true. Select one or more: a. Adding locking and unlocking statements (in arbitrary ways) to transactions is sufficient to assure database consistency in concurrent schedules. b. A conflict serializable schedule assures database consistency. c. The "B" in "B+-tree" stands for "Binary". d. The search key field/attribute of a primary index for a table does NOT have to be the primary key of the table. e. If an index is a sparse index, it MUST BE a primary index. f. It is a good idea to allow ONLY SERIAL schedules because they guarantee database consistency.
Question 25 Assume data is to be stored in a hash table using the following key sequence: 76, 84, 15, 31, 5, 21 Assume the hash table size is 8, the hash function used is the modulo function i.e. h(key) = key % table_size, und collisions are handled using linear probing. What's the content of the table after all keys are mapped to the hash table? List keys starting from table index 0 and on. Separate numbers by a comma and a single space, and indicate an empty slot with an X. If a data item can't be stored, indicate SO.