Attribute Level Locking to Improve Data Availability in a Distributed System

Distributed systems consist of a number of computers connected over anetwork in which numerous users are using such systems locally or via the Internet tomeet their requirements. As the system is multiple users’ environment, the lockcontrol is an essential part to control the concurrent accessing on the same data item.This system presents a lockable unit on the attributes of a record. So, the databaserecords increased in accessibility because the attributes are locked instead of the entirerow. This technique may allow several transactions to access the database rowsimultaneously by utilizing some attributes and keeping others available for othertransactions. In this thesis, concurrency control is mainly implemented by usingattribute level locking with the combination of three phases locking (which containread lock, write intent lock and write lock) in order to prevent dead lock and tocontrol concurrent processing for employee management system. This system isimplemented using C# programming language with Microsoft Visual Studio 2013 anddatabase engine is implemented with Microsoft SQL Server 2008 R2