突然才发现一个数据库的LGWR进程的跟踪文件scm2_lgwr_5690.trc有大量的告警信息，如下所示：
Warning: ;log write time 680ms, size 11569KB
*** ;2015-01-04 02:41:17.122
Warning: ;log write time 520ms, size 2764KB
*** ;2015-01-04 03:11:40.885
Warning: ;log write time 880ms, size 1KB
*** ;2015-01-04 03:24:04.357
Warning: ;log write time 500ms, size 1KB
*** ;2015-01-04 03:29:11.160
Warning: ;log write time 510ms, size 2KB
*** ;2015-01-04 03:30:22.383
Warning: ;log write time 540ms, size 2KB
*** ;2015-01-04 04:04:09.133
Warning: ;log write time 680ms, size 3KB
*** ;2015-01-04 04:15:53.617
Warning: ;log write time 620ms, size 25KB
*** ;2015-01-04 04:20:06.502
Warning: ;log write time 940ms, size 5KB
*** ;2015-01-04 04:31:11.049
Warning: ;log write time 520ms, size 43KB
*** ;2015-01-04 04:32:52.570
Warning: ;log write time 520ms, size 33KB
*** ;2015-01-04 04:33:22.023
Warning: ;log write time 1600ms, size 257KB
*** ;2015-01-04 04:33:22.609
Warning: log write time 590ms, size 443KB