NoSQL Schema Evolution and Big Data Migration at Scale II

该提案是DFG研究资助号（删除符号）的后续，我们一直致力于NoSQL数据存储支持的应用程序中的数据库模式演变。虽然许多NoSQL数据存储不强制使用固定的模式，但应用程序代码仍然会对存储的数据的结构进行假设。因此，应用程序代码强加了一个模式。随着应用程序代码的发展，这个模式也在发展。自2017年12月以来，我们一直在DFG授权（已删除签名）方面成功合作，解决了对管理NoSQL数据库模式及其演变的良好原则工具的迫切需求。虽然我们的工作仍在进行中，但我们已经做出了一系列真正的贡献，这些贡献导致了广受欢迎的出版物，特别是工作原型系统。到目前为止，我们的研究主要集中在单模型数据存储中逻辑NoSQL模式的演变上。有了这个后续建议，我们扩展到更一般的多库家族。虽然多存储库经常被推荐用于不断发展的数据密集型应用，但对多存储库中的模式进化的研究仍处于起步阶段：-截至目前，没有系统的方法来管理多存储库中的模式进化，涉及多个相互关联的存储特定逻辑模式。到目前为止，在NoSQL数据存储中没有可自动化的逻辑模式设计最佳实践。此外，模式设计必须是自适应的。-到目前为止，在NoSQL数据存储中，还没有很好的原则策略来优化物理模式，以适应w.r.t.模式进化。在这个后续的建议中，我们将在全局多存储模式、支持多存储的各个数据存储的逻辑模式以及它们的物理模式的级别上全面地解决这些紧迫的问题。我们调查了最新的研究现状，指出了当前的痛点和局限性，并提出了一系列新颖的、环环相扣的工作包，在这些工作包中我们研究了解决方案。对研究社区的一个可持续贡献是开发了第一个专门用于多存储库的模式演化基准。

This proposal is a follow-up on DFG research grant number (sign removed), where we have been targeting database schema evolution in applications backed by NoSQL data stores. While many NoSQL data stores do not enforce a fixed schema, the application code nevertheless makes assumptions about the structure of the data stored. Thus, the application code imposes a schema. Along with the application code, this schema evolves. We have been successfully collaborating on DFG grant (sign removed) since December 2017, addressing the dire need for well-principled tools managing NoSQL database schemas and their evolution. While our work is still ongoing, we have already made a range of genuine contributions leading to well-received publications, and in particular, working prototype systems. So far, our research has had a strong focus on the evolution of the logical NoSQL schema in single-model data stores. With this follow-up proposal, we expand to the more general family of polystores. While polystores are often recommended for continuously evolving and data intensive applications, research on schema evolution in polystores is still in its infancy:- As of today, there are no systematic approaches for schema evolution management in polystores, involving several interlinked store-specific logical schemas.- As of today, there are no automatable best practices for logical schema design in NoSQL data stores. Moreover, the schema design must be adaptive w.r.t. schema evolution.- As of today, there are no well-principled strategies for physical schema optimisation in NoSQL data stores that are adaptive w.r.t. schema evolution. In this follow-up proposal, we address these pressing issues holistically, on the level of the global polystore schema, the logical schemas of the individual data stores backing the polystore, as well as their physical schemas. We survey the research state-of-the-art, point out the current pain points and limitations, and present a sequence of novel and interlocking work packages in which we research solutions. One sustainable contribution to the research community is the development of the first schema evolution benchmark dedicated to polystores.