Subprocess cannot open system.duckdb (main process holds lock).
Now main process reads table_registry and passes configs as JSON
via stdin to subprocess. Subprocess never touches system.duckdb.
Three-pronged fix for DuckDB lock conflicts:
1. WAL mode on system.duckdb — enables concurrent readers + writer
2. Sync trigger runs extractor as subprocess (not background task) —
separate process = separate DuckDB connections, no lock conflict
3. Both extractor and orchestrator write to .tmp then atomic rename —
avoids lock conflict with API reads on extract.duckdb/analytics.duckdb
Fixes#9 permanently.
Schema v3: add is_public column to table_registry (default true).
src/rbac.py: can_access_table() checks admin bypass, public flag,
explicit permissions, wildcard bucket permissions.
API enforcement:
- manifest: filters tables by user access
- download: 403 if no access
- catalog: filters table list
- query: validates referenced tables against allowed list
New admin permissions API (/api/admin/permissions) for grant/revoke.
28 access control tests + 733 total tests passing.
