jump over corrupt index records and pages, which helps in dumping tables.
2 (SRV_FORCE_NO_BACKGROUND)
防止主线程和任何清除线程运行，如果清除操作会导致服务器挂掉，此选项有助于防止它。
Prevents the master thread and any purge threads from running. If a crash
would occur during the purge operation, this recovery value prevents it.
3 (SRV_FORCE_NO_TRX_UNDO)
恢复后不回滚事务。
Does not run transaction rollbacks after crash recovery.
4 (SRV_FORCE_NO_IBUF_MERGE)
如果插入到缓冲区的合并操作会导致系统崩溃，那么插入将不会被执行。
Prevents insert buffer merge operations. If they would cause a crash,
does not do them. Does not calculate table statistics.
5 (SRV_FORCE_NO_UNDO_LOG_SCAN)
启动数据库时，忽略撤消日志，InnoDB将未完成事务当作已经完成。
Does not look at undo logs when starting the database:
InnoDB treats even incomplete transactions as committed.
6 (SRV_FORCE_NO_LOG_REDO)
启动数据库时，忽略与恢复相关的前滚日志。
Does not do the redo log roll-forward in connection with recovery.
使用上述选项值时，您只能进行基本的SELECT查询，不能进行其他查询。
With this value, you might not be able to do queries other than a basic
SELECT * FROM t, with no WHERE, ORDER BY, or other clauses. More complex
queries could encounter corrupted data structures and fail.
If corruption within the table data prevents you from dumping the entire table
contents, a query with an ORDER BY primary_key DESC clause might be able to dump
the portion of the table after the corrupted part.