-- Restore the two UNIQUE indexes on `room_instance`. -- -- Generated from packages/domain/src/room-instance-db.ts (ROOM_INSTANCE_SCHEMA_DDL) — -- keep in sync. The DDL and migration 0004 have always declared them, but the deployed -- table carried only the non-unique `idx_room_instance_room_id`: the two `CREATE UNIQUE -- INDEX` statements never took, so nothing has enforced uniqueness on `id` or -- `photon_room_id` in production. Two rows sharing one `photon_room_id` were found — -- the signature of a replayed INSERT (same blob written twice), which the index would -- have refused. Without the `id` index the `MAX(id) + 1` allocation in -- createRoomInstance can also hand two concurrent matchmakes the same id, which the -- index would have failed loudly instead of silently minting two instances. -- -- A UNIQUE index refuses to build over duplicates, so they're removed first. Instances -- are live sessions, not records: of each duplicate set the earliest row (lowest rowid) -- is kept and the rest dropped. A replayed insert's twins are identical, so nothing is -- lost; presence rows point at instances by `id`, which the survivor still carries. -- Dedupe by `id` first so a row that is a duplicate on both counts is only counted once. DELETE FROM room_instance WHERE rowid NOT IN (SELECT MIN(rowid) FROM room_instance GROUP BY id); DELETE FROM room_instance WHERE rowid NOT IN (SELECT MIN(rowid) FROM room_instance GROUP BY photon_room_id); CREATE UNIQUE INDEX IF NOT EXISTS idx_room_instance_id ON room_instance (id); CREATE UNIQUE INDEX IF NOT EXISTS idx_room_instance_photon_room_id ON room_instance (photon_room_id);