CREATE TABLE platform_user_roles (
    id            BIGSERIAL PRIMARY KEY,
    user_id       BIGINT NOT NULL REFERENCES users(id),
    platform_role VARCHAR(20) NOT NULL,
    created_at    TIMESTAMPTZ NOT NULL DEFAULT NOW(),
    updated_at    TIMESTAMPTZ NOT NULL DEFAULT NOW(),
    deleted_at    TIMESTAMPTZ
);
CREATE UNIQUE INDEX uk_platform_user_role_active ON platform_user_roles(user_id, platform_role) WHERE deleted_at IS NULL;