The relational database may may never die -- at least not anytime soon -- but its days of glory appear to be over.
Relational databases, long a critical piece of enterprise software deployments, are now forced to share the stage with technologies better geared to accommodate newer data structures and modern hardware systems. Stalwart RDBMSes remain in place from software vendors such as IBM, Microsoft, and Oracle, all of which will continue to dominate such core functions as financial transactions. But NoSQL databases, as well as big data technologies such as Apache Hadoop and MapReduce, are where the action is.
[ IT users report that NoSQL offers speed, scalability, and flexibility. | Learn the basics of big data technologies. | Let InfoWorld's Data Explosion interactive iGuide help you manage today's explosion of the data you need to analyze and manage. ]
"The relational database as it stands is dead," says analyst Robin Bloor, chief analyst at the Bloor Group. "Its architecture is old, and it needs to be renewed."
Bloor reasons that RDBMSes were written for old hardware environments with single-CPU systems, a small amount of memory, and large stores of disk space. With the growing prominence of multi-CPU computers and solid-state disks, disk access is no longer as important. "The whole thing is changed. You're going from a train to an airplane," says Bloor. Solid-state disks are faster, so the ratio between disk and memory in terms of read speed will come down, he said.
The RDBMS has been devalued, says Jill McRae, a learning architect for business and intelligence systems at consulting firm Wright Robbins. "It never was completely there," she says, recalling statistics showing very little of the world's data is actually managed in relational systems.
The rise of NoSQL and "NewSQL"
McRae cites the emergence of NoSQL databases as "changing the scope of what a piece of data is." It's no longer primitive data types such as integers and floating points -- data could be a whole document. "[NoSQL] probably scares the hell out of DBAs because they're losing hold of their domain."
NoSQL features databases that are nonrelational, horizontally scalable, distributed, and open source. They can serve as a backing store for Web application servers, content management systems, structured event logging, server-side storage for mobile applications, and document storage, says Dwight Merriman, coauthor of the MongoDB NoSQL database.