SAML: A Self-Adjusting Multi-Granularity Locking Protocol for Object-oriented Databases
Deepa Saha, Joan Morrissey
Journal of Information Technology Review, Vol. 1, No. 2, 2010.
DOI: 
Link: http://www.dline.info/jitr/fulltext/v1n205.pdf
Abstract:
Object-oriented databases (OODBs) have the potential to be used for data-intensive, multi-user applications that are not well served by traditional databases. Despite the fact that there has been extensive research done for relational databases in the area of concurrency control, many of the approaches are not suitable for the complex data model of objectoriented databases. This paper presents a self-adjusting multi-granularity locking protocol (SAML) which facilitates choosing an appropriate locking granule according to the requirements of the transactions and encompasses less overhead and provides better concurrency compared to some of the existing protocols. Though there has been another adaptive multi-granularity protocol called AMGL [Chang, C.T.K. 2002], which provides the same degree of concurrency as SAML: SAML has been proven to have signifi cantly reduced the number of locks and hence the locking overhead compared to AMGL. Experimental results show that SAML performs the best when the workload is high in the system and transactions are long-lived.