ADR 0001 — Files are the truth; databases are caches

Status: accepted · 2026-09-13

Context. The private predecessor stored the log in Postgres/PostGIS and mirrored it to JSONL. A standard cannot require a database server.

Decision. The JSONL files under logbook/<YYYY>/<MM>.jsonl are the record. Any database is a derived index that may be deleted and rebuilt. verify and export read files only.

Consequences. Engines that need spatial queries bring their own index (SQLite + R*Tree by default; PostGIS as a plugin). Chain order is seq, not file order, because backfilled history lands in old month files.