-- 0002_missing.sql — track files that disappear from disk.
--
-- A rescan must not delete an item whose file is temporarily unavailable
-- (unmounted drive, NFS hiccup, user mid-reorganise). Deleting cascades into
-- progress, which is the one thing in this schema that cannot be regenerated.
-- Mark instead, and filter on read. A later pass can prune rows that have been
-- missing for a long time.

ALTER TABLE media_items ADD COLUMN missing INTEGER NOT NULL DEFAULT 0;
ALTER TABLE media_files ADD COLUMN missing INTEGER NOT NULL DEFAULT 0;

CREATE INDEX idx_items_library_missing ON media_items(library_id, missing);
CREATE INDEX idx_files_missing ON media_files(missing);