Live & Local Schema Change: Challenge Problems

TL;DR

This paper presents concrete challenge problems related to schema change in live and local-first programming, aiming to stimulate research and solutions for data and code mismatch issues during schema evolution.

Contribution

It introduces a set of specific schema change scenarios as challenge problems to guide future research in live and local-first programming environments.

Findings

Identifies key issues caused by schema changes in live and local-first systems

Proposes concrete scenarios to serve as benchmarks for future solutions

Aims to facilitate progress through well-defined challenge problems

Abstract

Schema change is an unsolved problem in both live programming and local-first software. We include in schema change any change to the expected shape of data, whether that is expressed explicitly in a database schema or type system, or whether those expectations are implicit in the behavior of the code. Schema changes during live programming can create a mismatch between the code and data in the running environment. Similarly, schema changes in local-first programming can create mismatches between data in different replicas, and between data in a replica and the code colocated with it. In all of these situations the problem of schema change is to migrate or translate existing data in coordination with changes to the code. This paper contributes a set of concrete scenarios involving schema change that are offered as challenge problems to the live programming and local-first communities. We hope that these problems will spur progress by providing concrete objectives and a basis for comparing alternative solutions.