<span><span>class</span> <span>Migrator</span> </span>{
    <span>private</span> SqlServerRepository sqlServerRepository;
    <span>private</span> MariaDBRepository mariaDBRepository;
    <span>private</span> MigrateHistoryRepository migrateHistoryRepository;

    <span><span>public</span> <span>void</span> <span>migrate</span><span>()</span> </span>{
        Thread newThread = <span>new</span> Thread(() -&gt; {
            <span>long</span> lastId = migrateHistoryRepository.getLastMigratedId();
            <span>while</span> (<span>true</span>) {
                List&lt;Entity&gt; entities = sqlServerRepository.findByIdGt(lastId);
                <span>if</span> (entities.isEmpty()) {
                    <span>break</span>;
                }
                mariaDBRepository.save(entities);
                lastId = entities.get(entities.size() - <span>1</span>).getId();
            }
        });
        newThread.start();
    }
}

<span><span>interface</span> <span>MigrateHistoryRepository</span> </span>{

    <span><span>void</span> <span>saveLastMigratedId</span><span>(<span>long</span> lastMigratedId)</span></span>;

    <span><span>long</span> <span>getLastMigratedId</span><span>()</span></span>;
}

<span><span>interface</span> <span>SqlServerRepository</span> </span>{

    <span>@EzyQuery</span>(<span>"SELECT e FROM Entity e WHERE e.id &gt; ?0"</span>)
    <span>List&lt;Entity&gt; <span>findByIdGt</span><span>(<span>long</span> idExclusive)</span></span>;
}

<span><span>interface</span> <span>MariaDBRepository</span> </span>{

    <span><span>void</span> <span>save</span><span>(Entity entity)</span></span>;

    <span><span>void</span> <span>save</span><span>(List&lt;Entity&gt; entities)</span></span>;
}

<span>@Data</span>
<span><span>class</span> <span>Entity</span> </span>{
    <span>private</span> <span>long</span> id;
}