-- Atomic facts ledger schema
-- Enforces atomic uniqueness via SHA-256 hash primary key

CREATE TABLE IF NOT EXISTS atomic_facts (
    hash CHAR(64) PRIMARY KEY,
    sentence TEXT NOT NULL,
    category TEXT NOT NULL,
    source TEXT NOT NULL,
    created_at TIMESTAMPTZ NOT NULL DEFAULT now()
);

-- Helpful indexes
CREATE INDEX IF NOT EXISTS atomic_facts_category_idx ON atomic_facts(category);
CREATE INDEX IF NOT EXISTS atomic_facts_created_at_idx ON atomic_facts(created_at);