A data construct that often appears in business applications is the hierarchical data structure. Hierarchy captures the parent-child relationship often between the same object. For instance, a company structure captures the reporting line between employees. A business organization captures the relationship between parent companies and subsidiaries. Territory hierarchies in Sales. Book of accounts in financial applications.
Due to the self-referencing nature of hierarchy, querying the structure efficiently along with its associated data can be a challenge for RDBMSs, particularly from a performance perspective. In this article, I will discuss how a traditional RDBMS handles hierarchical queries, the challenges that it has to deal with, and how this issue can be similarly addressed with Couchbase N1QL and Couchbase GSI.