-- Preserve the matcher-selected topology through the proposal response window.
-- These fields are nullable for already-created proposals during a rolling
-- deployment; new matcher-created proposals always populate them before they
-- can be promoted to an ALLOCATING match.
ALTER TABLE proposals
    ADD COLUMN match_region TEXT CHECK (match_region IN ('EU', 'NA')),
    ADD COLUMN match_protocol INTEGER CHECK (match_protocol > 0);

ALTER TABLE proposal_participants
    ADD COLUMN team INTEGER CHECK (team IN (0, 1)),
    ADD COLUMN slot INTEGER CHECK (slot BETWEEN 0 AND 5);

CREATE UNIQUE INDEX proposal_participants_unique_slot
    ON proposal_participants (proposal_id, slot)
    WHERE slot IS NOT NULL;