Data schema does matter, even in NoSQL systems!

Abstract

Abstract-A Schema-less NoSQL system refers to solutions where users do not declare a database schema and, in fact, its management is moved to the application code. This paper presents a study that allows us to evaluate, to some extent, the data structuring impact. The decision of how to structure data in semi-structured databases has an enormous impact on data size, query performance and readability of the code, which influences software debugging and maintainability. This paper presents an experiment performed using MongoDB along with several alternatives of data structuring and a set of queries having increasing complexity. This paper introduces an analysis regarding the findings of such an experiment.

Towards Quality Analysis for Document Oriented Bases

“…However, the characteristics of the data structure have a strong impact on several aspects such as the size of the database, query performance and code readability of queries. The experiments presented in [2] confirm that influence. Our work is motivated by the analysis of how such aspects influence the maintainability and usability of the database as well as applications.…”

“…In Figure 7, we introduce an example with nine structuring alternatives. This case study was already used in the work with MongoDB databases presented in [2], where we discussed the impact of the data-structures on the query evaluation. Here we are considering a similar application to analyze schema alternatives using the metrics.…”

“…This flexibility enables rapid initial development and permits many data structure possibilities for the same information. The choice is quite crucial for its potential impact on several aspects of application quality [2]. Indeed, each structure may have advantages and disadvantages regarding several aspects, such as the memory footprint of the document base, data redundancy, navigation cost, data access or program readability and maintainability.…”

Évaluation et comparaison de structures de données orientées document

“…La manière dont sont structurées les données a un fort impact sur la taille de la base, les performances des requêtes et la lisibilité du code des requêtes, ce influence la maintenabilité et l'usabilité de la base ainsi que de ses applications. Cela a été constaté de manière expérimentale (Gómez et al, 2016) où plusieurs patrons de comportement ressortent. Notamment, les collections avec des documents imbriqués ont un impact positif sur les requêtes qui suivent l'ordre d'imbrication.…”

“…Cela octroie une grande flexibilité à l'utilisateur tout en introduisant une complexité dans l'accès aux données. La manière de structurer les données est importante car elle a un impact sur divers aspects de la base de documents et des applications qui les utilisent (Gómez et al, 2016 ;Gomez, 2018). Les choix de structuration peuvent présenter des avantages et des inconvénients en matière d'empreinte mémoire, redondance de données engendrée, coût de navigation dans les structures et d'obtention de certaines données, et lisibilité des programmes.…”