SQLite WAL Mode Works Reliably Across Docker Containers Sharing a Volume

Summary

Simon Willison published research demonstrating that SQLite's Write-Ahead Logging (WAL) mode reliably supports concurrent database access when two Docker containers share a named volume on the same host. The experiment, conducted on Docker Desktop for macOS, showed real-time propagation of database changes between containers and effective memory-mapped file sharing via the .db-shm file. This finding is relevant to lightweight deployment architectures where SQLite serves as an embedded database