How do Database Systems Handle Transaction Failures? - GeeksforGeeks (2024)

Recovery from failures in Two Phase Commit Protocol (Distributed Transaction)

Prerequisite: Two-Phase Commit ProtocolIn the 2-phase commit protocol, the sites contributing to a distributed transaction and the coordinator that is managing the whole transaction globally may fail or crash, and this could lead to the whole transaction failure. Since unanimity is required in order to commit a distributed transaction successfully

Transaction Isolation Levels in DBMS

Prerequisite - Concurrency control in DBMS, ACID Properties in DBMS As we know, in order to maintain consistency in a database, it follows ACID properties. Among these four properties (Atomicity, Consistency, Isolation, and Durability) Isolation determines how transaction integrity is visible to other users and systems. It means that a transaction

On Line Transaction Processing (OLTP) System in DBMS

On-Line Transaction Processing (OLTP) System refers to the system that manage transaction oriented applications. These systems are designed to support on-line transaction and process query quickly on the Internet. For example: POS (point of sale) system of any supermarket is a OLTP System. Every industry in today's world use OLTP system to record t

Difference between Data Warehousing and Online transaction processing (OLTP)

1. Data Warehousing : Data Warehousing is a technique that gathers or collects data from different sources into a central repository, or, in other words, a single, complete, and consistent store of data that is obtained from different sources. It is a powerful database model that enhances the user ability to analyze huge, multidimensional datasets;

Two Phase Commit Protocol (Distributed Transaction Management)

Consider we are given with a set of grocery stores where the head of all store wants to query about the available sanitizers inventory at all stores in order to move inventory store to store to make balance over the quantity of sanitizers inventory at all stores. The task is performed by a single transaction T that's component Tn at the nth store a

Introduction to Transaction Processing

Single user system : In this at-most, only one user at a time can use the system. Multi-user system : In the same, many users can access the system concurrently. Concurrency can be provided through : Interleaved Processing - In this, the concurrent execution of processes is interleaved in a single CPU. The transactions are interleaved, meaning the

Transaction Control in DBMS

The transaction is a single logical unit that accesses and modifies the contents of the database. Transactions access data using read and write operations. Transaction is a single operation of processing that can have many operations. Transaction is needed when more than one user wants to access same database. Transaction has ACID properties. ACID

Transaction Management

Transactions are a set of operations used to perform a logical set of work. It is the bundle of all the instructions of a logical operation. A transaction usually means that the data in the database has changed. One of the major uses of DBMS is to protect the user's data from system failures. It is done by ensuring that all the data is restored to

Transaction in DBMS

In Database Management Systems (DBMS), a transaction is a fundamental concept representing a set of logically related operations executed as a single unit. Transactions are essential for handling user requests to access and modify database contents, ensuring the database remains consistent and reliable despite various operations and potential inter

Transaction States in DBMS

Transaction in DBMS is a set of logically related operations executed as a single unit. These logic are followed to perform modification on data while maintaining integrity and consistency. Transactions are performed in a way that concurrent actions from different users don't malfunction the database. Transfer of money from one account to another i

Difference between Operational Systems and Informational Systems

1. Operational Systems : An operational system is a generally known term in data warehousing that specifies a system which is used to maintain records of daily business transactions in an organization. Operational system is also termed as Online Transaction Processing (OLTP). Operational systems have to deal with the running data values and consist

Database Management Systems | Set 2

Following Questions have been asked in GATE 2012 exam. 1) Which of the following statements are TRUE about an SQL query? P: An SQL query can contain a HAVING clause even if it does not a GROUP BY clause Q: An SQL query can contain a HAVING clause only if it has a GROUP BY clause R: All attributes used in the GROUP BY clause must appear in the SELEC

Database Management Systems | Set 3

Following Questions have been asked in GATE 2012 exam. 1) Consider the following transactions with data items P and Q initialized to zero: T1: read (P) ; read (Q) ; if P = 0 then Q : = Q + 1 ; write (Q) ; T2: read (Q) ; read (P) ; if Q = 0 then P : = P + 1 ; write (P) ; Any non-serial interleaving of T1 and T2 for concurrent execution leads to (A)

Database Management Systems | Set 4

Following Questions have been asked in GATE 2011 exam. 1. Consider a relational table with a single record for each registered student with the following attributes. 1. Registration_Number:< Unique registration number for each registered student 2. UID: Unique Identity number, unique at the national level for each citizen 3. BankAccount_Number:

Database Management Systems | Set 5

Following Questions have been asked in GATE CS 2010 exam. 1) A relational schema for a train reservation database is given below. Passenger (pid, pname, age) Reservation (pid, class, tid) Table: Passenger pid pname age ----------------- 0 Sachin 65 1 Rahul 66 2 Sourav 67 3 Anil 69 Table : Reservation pid class tid --------------- 0 AC 8200 1 AC 820

Database Management Systems | Set 6

Following questions have been asked in GATE 2009 CS exam. 1) Consider two transactions T1 and T2, and four schedules S1, S2, S3, S4 of T1 and T2 as given below: T1 = R1[X] W1[X] W1[Y] T2 = R2[X] R2[Y] W2[Y] S1 = R1[X] R2[X] R2[Y] W1[X] W1[Y] W2[Y] S2 = R1[X] R2[X] R2[Y] W1[X] W2[Y] W1[Y] S3 = R1[X] W1[X] R2[X] W1[Y] R2[Y] W2[Y] S1 = R1[X] R2[Y]R2[X

Database Management Systems | Set 7

Following questions have been asked in GATE 2008 CS exam. 1) Let R and S be two relations with the following schema R (P,Q,R1,R2,R3) S (P,Q,S1,S2) Where {P, Q} is the key for both schemas. Which of the following queries are equivalent? (A) Only I and II (B) Only I and III (C) Only I, II and III (D) Only I, III and IV Answer (D) In I, Ps from natura

Database Management Systems | Set 10

Following questions have been asked in GATE CS 2005 exam. 1) Let r be a relation instance with schema R = (A, B, C, D). We define r1 = 'select A,B,C from r' and r2 = 'select A, D from r'. Let s = r1 * r2 where * denotes natural join. Given that the decomposition of r into r1 and r2 is lossy, which one of the following is TRUE? (a) s is subset of r

Database Management Systems | Set 8

Following questions have been asked in GATE 2005 CS exam. 1) Which one of the following statements about normal forms is FALSE? (a) BCNF is stricter than 3NF (b) Lossless, dependency-preserving decomposition into 3NF is always possible (c) Lossless, dependency-preserving decomposition into BCNF is always possible (d) Any relation with two attribute

Database Management Systems | Set 9

Following questions have been asked in GATE 2006 CS exam. 1) Consider the following log sequence of two transactions on a bank account, with initial balance 12000, that transfer 2000 to a mortgage payment and then apply a 5% interest. 1. T1 start 2. T1 B old=12000 new=10000 3. T1 M old=0 new=2000 4. T1 commit 5. T2 start 6. T2 B old=10000 new=10500

Database Management Systems | Set 11

Following questions have been asked in GATE CS 2007 exam. 1) Information about a collection of students is given by the relation studinfo(studId, name, sex). The relation enroll(studId, courseId) gives which student has enrolled for (or taken) that course(s). Assume that every course is taken by at least one male and at least one female student. Wh

Applications of Commercial Deductive Database Systems

A Deductive Database is a type of database that can make conclusions or we can say deductions using a sets of well defined rules and fact that are stored in the database. In today's world as we deal with a large amount of data, this deductive database provides a lot of advantages. It helps to combine the RDBMS with logic programming. To design a de

Differences between Operational Database Systems and Data Warehouse

The Operational Database is the source of data for the information distribution center. It incorporates point by point data utilized to run the day to day operations of the trade. The information as often as possible changes as upgrades are made and reflect the current esteem of the final transactions. Operational Database Administration Frameworks

Difference between Single User and Multi User Database Systems

Introduction : Single-user and multi-user database systems refer to the number of users who can access a database system simultaneously. A single-user database system is designed to be used by only one user at a time. It is typically installed on a single computer and can only be accessed by the user who installed it or the user who is currently lo

Date's Twelve Rules for Distributed Database Systems

Distributed databases brings advantages of distributed computing which consists huge number of processing elements, elements may be heterogeneous. Elements are connected with network which help in performing the assigned task. Basically, it is used to solve problem by distributing it into number of smaller problems and solve smaller problems in coo

Types of Database Management Systems

A Database Management System (DBMS) is a software system that is designed to manage and organize data in a structured manner. It allows users to create, modify, and query a database, as well as manage the security and access controls for that database. What is DBMS?A DBMS (Database Management System) is a software or technology used to manage data

How to pre populate database in Android using SQLite Database

Introduction : Often, there is a need to initiate an Android app with an already existing database. This is called prepopulating a database. In this article, we will see how to pre-populate database in Android using SQLite Database. The database used in this example can be downloaded as Demo Database. To prepopulate a SQLite database in an Android

Difference between Database Administrator (DBA) and Database Engineer

1. Database Administrator (DBA) : A database administrator is responsible for management of a database (DB). His/her duties involve administration, performance tuning, optimization, backup and recovery of a database. The DBA is more of a management profile. The DBA also enhances the Logical Design of the database. He/she may be guided by the Databa

Difference between Centralized Database and Distributed Database

1. Centralized Database: A centralized database is basically a type of database that is stored, located as well as maintained at a single location only. This type of database is modified and managed from that location itself. This location is thus mainly any database system or a centralized computer system. The centralized location is accessed via