Oracle 12c实现了多LGWR管理,这就引入了LG00-LG99一系列的后台进程;下面是LGnn的详细描述:On multiprocessor systems,
LGWR creates worker processes to improve the performance of writing to the redo log. LGWR workers are not used
when there is a SYNC standby destination. Possible processes include LG00-LG99. 从描述中可以看到,LGnn与CPU的个数有关.
一个CPU下的LGWR进程情况:
[oracle@dbserver12c ~]$ ps -ef|grep ora_lg* oracle 5532 1 0 11:01 ? 00:00:00 ora_lgwr_orcl12c oracle 5540 1 0 11:01 ? 00:00:00 ora_lreg_orcl12c oracle 6572 6531 0 12:47 pts/3 00:00:00 grep ora_lg*
两个CPU下的LGWR进程情况:
[oracle@dbserver ~]$ ps -ef|grep ora_lg* oracle 28702 1 0 14:08 ? 00:00:00 ora_lgwr_orcl oracle 28706 1 0 14:08 ? 00:00:00 ora_lg00_orcl oracle 28708 1 0 14:08 ? 00:00:00 ora_lg01_orcl oracle 28714 1 0 14:08 ? 00:00:00 ora_lreg_orcl oracle 29632 29597 0 15:14 pts/4 00:00:00 grep ora_lg* |