Back up the local data.mdb file

We need to back up the /objectbox/objectbox/data.mdb file, and we need to ensure that the database is complete and that the current data is not being written. We don't currently find an API that can be used.

Our current solution is to start a transaction and copy the database file in the transaction to avoid other writes during the copying process. Will it cause other problems?

sBoxStore.runInTx(new Runnable() {
        @Override
        public void run() {                
               use FileUtils copy data.mdb to backup_data.mdb
        }
    });

首先检查 issue 中描述的 data.mdb 备份场景和 Store.runInTx 方法，然后确定可用的数据库 API 和事务 API。确定在没有并发写入的情况下生成完整备份的受支持方式；当 API 或其限制以及一致性保证得到明确说明时，即视为完成。