IS411P Distributed Database Systems Quiz 2

<p>Ensure atomicity and durability of distributed transactions</p> Signup and view all the answers

<p>Maintain consistency between concurrent transactions</p> Signup and view all the answers

<p>Providing fault tolerance and reliability</p> Signup and view all the answers

<p>By assigning each transaction a unique timestamp at initiation</p> Signup and view all the answers

<p>Allowing each site to autonomously assign timestamps based on its local counter</p> Signup and view all the answers

<p>A local counter value and a site identifier</p> Signup and view all the answers

<p>Assigning timestamps to transactions and determining the sites where data items are stored</p> Signup and view all the answers

<p>It enforces a specific order of execution for conflicting operations</p> Signup and view all the answers

<p>The operation is accepted and executed immediately</p> Signup and view all the answers

<p>To identify the oldest transaction that has read or written (updated) each data item</p> Signup and view all the answers

<p>It causes excessive restarts of transactions due to no delaying</p> Signup and view all the answers

<p>Basic TO algorithm never causes operations to wait, whereas conservative TO algorithms introduce waiting times.</p> Signup and view all the answers

<p>By delaying each operation until there is no conflict with previously scheduled operations</p> Signup and view all the answers

<p>To lower system overhead and reduce operational disruptions caused by restarts</p> Signup and view all the answers

<p>The excessive restarts of transactions due to no delaying</p> Signup and view all the answers

<p>Reduction of system resource utilization through delayed execution</p> Signup and view all the answers

<p>A transaction is a collection of actions that make consistent transformations of system states while preserving system consistency.</p> Signup and view all the answers

<p>Concurrency control algorithms enforce the isolation property so that concurrent transactions see a consistent database state and leave the database in a consistent state.</p> Signup and view all the answers

<p>Reliability measures enforce atomicity and durability.</p> Signup and view all the answers

<p>The primary role of data replication in distributed database systems is to enhance reliability and availability.</p> Signup and view all the answers

<p>The main function of distributed transaction processing is to coordinate transactions that access multiple distributed database nodes.</p> Signup and view all the answers

<p>The main purpose of web data management is to manage and process large volumes of data generated from web applications and services.</p> Signup and view all the answers

<p>To establish a serialization order and execute transactions accordingly.</p> Signup and view all the answers

<p>Each site autonomously assigns timestamps based on its local counter, appending its own identifier to the counter value.</p> Signup and view all the answers

<p>The timestamp consists of a local counter value and a site identifier.</p> Signup and view all the answers

<p>The coordinating TM assigns timestamps to transactions, determines the storage sites of data items, and sends relevant operations to these sites.</p> Signup and view all the answers

<p>According to the TO Rule, a conflicting operation Oij is executed before another conflicting operation Okl if and only if ts(Ti) &lt; ts(Tk).</p> Signup and view all the answers

<p>The basic TO algorithm never causes deadlocks.</p> Signup and view all the answers

<p>The basic TO algorithm checks each new operation against conflicting ones and rejects it if the transaction is younger than all conflicting ones, causing a restart.</p> Signup and view all the answers

<p>The conservative TO algorithm aims to reduce the number of transaction restarts.</p> Signup and view all the answers

<p>Conservative TO algorithms delay each operation instead of causing immediate restarts.</p> Signup and view all the answers

<p>The preferred method is for each site to autonomously assign timestamps based on its local counter, appending its own identifier to the counter value.</p> Signup and view all the answers

<p>The conservative TO algorithm aims to lower system overhead by reducing the number of transaction restarts.</p> Signup and view all the answers

<p>The basic TO algorithm may potentially cause a transaction to restart numerous times.</p> Signup and view all the answers