create table mining_tasks
(
    task_id bigint not null
        constraint mining_tasks_pk
            primary key,
    sp_id   bigint,
    epoch   bigint,
    constraint mining_tasks_sp_epoch
        unique (sp_id, epoch)
);

create table mining_base_block
(
    id        bigserial not null
        constraint mining_base_block_pk
            primary key,
    task_id   bigint    not null
        constraint mining_base_block_mining_tasks_task_id_fk
            references mining_tasks
            on delete cascade,
    block_cid text      not null
        constraint mining_base_block_cid_k
            unique
);