Snapshot Isolation And There Validation Steps For Update Transactions And Serializability Issues

atabase is a collection of data which describes the activities of one or more organizations in a well-defined structure and the structure of a database is specific and it has a purpose. Database Management System (DBMS) is used to control or organize the data in a database. Database Management System (DBMS) is also used for maintaining large collections of data. Distributed database can be defined as a collection of various databases which can be stored at different computer network locations. In this paper we discuss about Distributed Databases, their advantages and disadvantages.

Our propose approach is single database scan approach which all transactions read only one time. Initially, SIL and PTable are empty. At first time interval transaction $\left\{a,b,g,f\right\}$ is read and updates SIL with items $\left\{a\right\}$, $\left\{b\right\}$, $\left\{g\right\}$ and $\left\{f\right\}$ and set their timeset (TS) value 1 which represents occurred time. In the first row of table \ref{Figure:example1} shows SIL and PTable generated after the first timestamp. After second timestamps the SIL and PTable updated shown in second row of table \ref{Figure:example1} At timestamp three, transactions $\left\{a,b,c,e,f\right\}$ with time 3 updates TS adding time 3 and generated descriptors (D) in SIL. For an item $\left\{a\right\}$

Most database ensure that they follow the ACID (Atomicity, Consistency, Isolation, Durability) properties to ensure the transactions are reliable. The studies show that stores that guarantee ACID property generally have poor availability. As a result, Dynamo focusses on application that have weaker consistency.

Coronel, C. (2013). Database Systems: Design, Implementation, and Management, Tenth Edition. Mason, Ohio, United States: Cengage Learning.

Relational database contains data records that do not have a preset of relationships, permitting the user to define his or her relationship when accessing the data. Since users have much control over the data being accessed, relational databases can perform a variety of tasks. Such as defining the database; querying the database; adding, editing, and deleting data from the database; modifying the structure of the database; securing data from public access; communicating within the network; and exporting and importing data (Murthy, 2008).

In order to overcome these limitations, a new database model known as Not Only SQL (NoSQL) database emerged with a set of new features. The main objective of NoSQL is not to discard SQL, but to be used as an alternative database data model for new features [1] [2] [3]. NoSQL database increases the performance of relational databases by a set of new characteristics and advantages. In contrast to relational databases, NoSQL databases introduced an additional feature that provides flexible and horizontal scalability and taking advantage of new clusters. The rise of NoSQL provides cost-effective management of data in modern web applications. With its new features, NoSQL can be used with applications that have a large transaction, and require low-latency access to huge datasets, service availability while

3.11. Suppose that each of the following Update operations is applied directly to the database state shown in Figure 3.6. Discuss all integrity constraints violated by each operation, if any, and the different ways of enforcing these constraints.

I, Simon Hedley have been assigned the responsibility by Dazzling Dogs to analyse the key issues in

Replication: An approach to enhance consistency in large Database clusters. Ayyapa Reddy Pasam, ayyappayouth@gmail.com Abstract Database systems implemented in parallel computers is called Database clustering.

Though non-relational databases have been around since the 1960s, many companies have used relational databases to store data[2] but over the past decade with companies generating vast amounts of data, relational databases are unable to effectively manage these large data collections[1]. An ever increasing amount of companies is now, however, turning to non-relational databases known as NoSQL databases as they are more effective at handling these large amounts of data thus the reason we have seen an increase in its popularity over the past decade[2]. The term NoSQL database which stands for Not Only SQL[3] is defined as a database that

In an increasingly competitive global landscape, there is no denying the importance of relational databases to organizations these days. They are a great tool for controlling, analyzing, recording, storing and monitoring processes and transactions throughout all functional aspects of the organization. While the benefits provided by relational databases are instrumental to the overall operation of an organization, traditional databases still have their limitations. This is where SAP HANA comes in. SAP HANA is probably best described as new form of database that operates as an in-memory data platform that is capable of processing large amounts of data in real-time. With its capability to simultaneously handle both transaction processing

The storage integrity and query integrity of a database are two of the most important functions that providers can offer, in addition to complex encryption and firewalls to provide additional security in the virtual environment. Each provider can offer a streamlined plan to implement a database solution along

Also, its robustness needs to be proven reliable with good uptime to satisfy service level agreements. This is necessary especially to professionals who need to store data without experiencing any data loss or data redundancy. It also needs to meet the needs of ACID which means the enterprise application should be atomic, consistent, isolated, and durable for its transactions that way it enables the support of several document transaction formats.

Earlier the heterogeneous systems integration is a major issue. Therefore it has to be considered if the system proposed is amenable to multiple platforms and will give the same results. There are many applications available to enforce this, but it is to be borne in mind that in a data management system many components have to be integrated with the system and the layering of these components becomes critical. (Thuraisingham, 2001) But the requirements today have gone beyond the traditional DBMS and the system is expected too seamlessly perform varied functions like tracking functions, data analysis and reporting, vendor

Ans ;- a) database mirroring: - Database reflecting is an answer for expanding the accessibility of a SQL Server database. Reflecting is actualized on a for each database premise and works just with databases that utilization the full recuperation model. Database reflecting was presented with Microsoft SQL Server 2005 innovation that can be utilized to outline high-accessibility and elite answers for database repetition. It is intended to keep up a hot standby server with a transitionally reliable duplicate of the database. Reflecting is practical, fast, obliges no extraordinary equipment, and guarantees value-based consistency. This article will portray the distinctive methods of database reflecting and how it is not the same as different advancements. Here won 't get into the specifics of the SQL Server 2008 upgrades however will take database reflecting is a basically programming answer for expanding database accessibility. Reflecting is actualized on a for every database premise and works just with databases that utilization the full recuperation model. The straightforward and mass logged recuperation models don 't bolster database reflecting. Database reflecting is bolstered in SQL Server Standard and Enterprise. Database reflecting offers considerable accessibility and gives a simple to-oversee option or supplement to failover grouping or log shipping. At the point when a database reflecting session is