Querying collections of tree-structured records in the presence of within-record referential constraints

TL;DR

This paper explores querying tree-structured data with internal referential constraints, highlighting challenges and proposing considerations for query evaluation in such constrained environments.

Contribution

It introduces a formal model for referential constraints within tree-structured records and discusses the implications for query processing.

Findings

Identifies challenges in query evaluation with internal constraints

Proposes a formal framework for referential constraints in tree data

Highlights impact on existing query evaluation techniques

Abstract

In this paper, we consider a tree-structured data model used in many commercial databases like Dremel, F1, JSON stores. We define identity and referential constraints within each tree-structured record. The query language is a variant of SQL and flattening is used as an evaluation mechanism. We investigate querying in the presence of these constraints, and point out the challenges that arise from taking them into account during query evaluation.