因为我们在协议中没有数据库保证能提交或回滚(参阅步骤12)这一点，所以数据库可以不执行任何写人操作。
It might not perform any write operations, because we haven't gotten to the point in the protocol where the database guarantees being able to commit or rollback (see step 12).
将分割镜像初始化为快照时，将执行崩溃恢复，回滚所有未提交的事务，并使数据库可以被所有读或写操作访问。
The initialization of the split mirror as snapshot performs a crash recovery, rolls back all uncommitted transactions, and makes the database available for any read or write operation.
其中，三种常见的策略为：回写（writeback）、预定（ordered）和数据（data）。
Three of the most common strategies are writeback, ordered, and data.
第一个是ADO.NETDataSet，它能够回写更改的集合到数据库。
First up is the ADO.NET DataSet, which is quite capable of writing back change sets to databases.
当将内容重新写回到原始数据库文件时，一个回滚日志或者写前日志wal文件将会被使用，正如它为其它数据库事务服务一样。
When overwriting the original, a rollback journal or write-ahead log WAL file is used just as it would be for any other database transaction.
当将内容重新写回到原始数据库文件时，一个回滚日志或者写前日志wal文件将会被使用，正如它为其它数据库事务服务一样。
When overwriting the original, a rollback journal or write-ahead log WAL file is used just as it would be for any other database transaction.
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