Increasing database concurrency control based on attribute level locking
Khaled Saleh Maabreh, Alaa Al-Hamami · 2008
Database is distinguished from the file system by the ability to work on the multi-user environment. This use needs specific techniques to protect the consistency and integrity of data contained in the database. The most popular technique used to attain the data protection (serializability) is locking (i.e., each transaction reserves access to the data it uses). Locking is done by following some rules (locking protocol) and according to compatibility function among different lock types (read or write), where a read is not compatible with a write. This research aims to increase the granularity hierarchy tree one more level down to include the attribute level, i.e. locking will be done at the attribute level to allow several transactions to access the same row simultaneously. The suggested level is expected to decrease the user competition for acquiring data items and to increase the performance of the database. However, this will increase the overhead on the database. By increasing the hierarchy tree one more level down to cover the attributes, the number of database lockable units is expected to increase, because the transaction is lock only the attributes it needs, So in the proposed approach, the database size is increased, because of using the field as lockable units, and the competition parts among transactions is decreased which causes the probability of conflicts to be decreased as well.