CREATE TABLE public.user_memberships (
    id UUID PRIMARY KEY,
    user_id UUID NOT NULL REFERENCES users(id) ON DELETE CASCADE,
    tenant_id UUID NOT NULL REFERENCES public.tenants(tenant_id) ON DELETE CASCADE,
    role TEXT NOT NULL,
    created_at TIMESTAMPTZ NOT NULL DEFAULT NOW(),
    updated_at TIMESTAMPTZ NOT NULL DEFAULT NOW(),
    UNIQUE (user_id, tenant_id)
);

CREATE INDEX user_memberships_tenant_id_idx ON public.user_memberships (tenant_id);
CREATE INDEX user_memberships_user_id_idx ON public.user_memberships (user_id);