CREATE TABLE IF NOT EXISTS graph_revision (
    singleton INTEGER PRIMARY KEY CHECK(singleton = 1),
    revision INTEGER NOT NULL DEFAULT 0
);
INSERT OR IGNORE INTO graph_revision(singleton) VALUES (1);
CREATE TABLE IF NOT EXISTS trust_cache (
    cache_key TEXT PRIMARY KEY,
    result TEXT NOT NULL,
    expires_us INTEGER NOT NULL
);
CREATE TABLE IF NOT EXISTS trust_dependencies (
    cache_key TEXT NOT NULL REFERENCES trust_cache(cache_key) ON DELETE CASCADE,
    author TEXT NOT NULL,
    record_key TEXT NOT NULL,
    PRIMARY KEY(cache_key, author, record_key)
);