Big Data Computing Applications - Guide to Cloud Computing for Business and Technology Managers - page 466

3. Document-centric databases are good where the data are difficult
to structure. Web pages and blog entries are two oft-quoted exam-
ples. Unlike RDBMS, which impose structure by their very nature,
document-centric databases allow free-form data to be stored. The
onus is then on the data retriever to make sense of the data that are
stored.
21.5 Summary
This chapter introduces big data systems that are associated with big volume,
variety, and velocity. It describes the characteristic features of such systems
including big data architecture, row versus column-oriented data layouts,
NoSQL data management, in-memory computing, and developing big data
applications. In the later part of the chapter, it provides a brief on the vari-
ous types of NoSQL databases including column-oriented stores, key-value
stores, document-oriented databases, and graph stores.