-- Stars and topics (hub spec §6: explore).

CREATE TABLE stars (

    account_id INTEGER NOT NULL REFERENCES accounts(id) ON DELETE CASCADE,

    repo_id    INTEGER NOT NULL REFERENCES repositories(id) ON DELETE CASCADE,

    at_ms      INTEGER NOT NULL,

    PRIMARY KEY (account_id, repo_id)

);

CREATE INDEX stars_by_repo ON stars (repo_id);

-- Space-separated, lower case.

ALTER TABLE repositories ADD COLUMN topics TEXT NOT NULL DEFAULT '';