PAQO

Nicholas L. Farnan, Adam J. Lee, Panos K. Chrysanthis, Ting Yu
2013 Proceedings of the VLDB Endowment  
Although the declarative nature of SQL provides great utility to database users, its use in distributed database management systems can leave users unaware of which servers in the system are evaluating portions of their queries. By allowing users to merely say what data they are interested in accessing without providing guidance regarding how to retrieve it, query optimizers can generate plans with unintended consequences to the user (e.g., violating user privacy by revealing sensitive portions
more » ... of a user's query to untrusted servers, or impacting result freshness by pulling data from stale data stores). To address these types of issues, we have created a framework that empowers users with the ability to specify constraints on the kinds of plans that can be produced by the optimizer to evaluate their queries. Such constraints are specified through an extended version of SQL that we have developed which we call PASQL. With this proposal, we aim to demonstrate PAQO, a version of PostgreSQL's query optimizer that we have modified to produce plans that respect constraints specified through PASQL while optimizing userspecified SQL queries in terms of performance.
doi:10.14778/2536274.2536309 fatcat:jvef66sbsfa3rmk7tvnmnc3mju