在Oracle中的v$log动态视图中有一个Sequence列，在Oracle中这个列的值称为Log Sequence Number。
Log sequence number
Whenever Oracle (or more precisely, the log writer process) writes to another online redo log file group (also referred to as log switch), the log sequence number increments by one.
If the database is opened with reset logs, the log sequence number is reset to 1.
Whenever Oracle (or more precisely, the log writer process) writes to another online redo log file group (also referred to as log switch), the log sequence number increments by one.
If the database is opened with reset logs, the log sequence number is reset to 1.
意思就是在每次log writer进程切换联机日志组的时候，切换后的日志组的log sequence number为前一个日志组加一，当使用reset logs打开数据库时，则log sequence number重置为1.
--EOF--