文档解释
ORA-01197: thread string only contains one log
Cause: During CREATE CONTROLFILE all threads represented in the logs must be represented by at least two logs. A “last log” and a second log. The named thread does not contain two such logs.
Action: Either find more logs from the named thread. Or use the RESETLOGS option to CREATE CONTROLFILE.
ORA-01197错误，表示线程中只包含一个日志，这表示类型为“归档备份”的多个线程应该具有更多的日志文件，如果没有，则可能会出现ORA-01197错误。
Oracle官方文档定义：ORA-01197：thread string only contains one log file – Archival required。
正常处理方法及步骤
1、检查添加是否正确或修复多源日志文件；
2、检查多源日志文件是否已被打开，如果没有则应该打开；
3、使用ALTER SYSTEM SWITCH LOGFILE命令连接多个日志文件，完成归档日志备份。
