12c archive_lag_targe强制日志切换

12c R1测试环境

ARCHIVE_LAG_TARGET forces a log switch after the specified amount of time elapses.

A 0 value disables the time-based thread advance feature; otherwise, the value represents the number of seconds. Values larger than 7200 seconds are not of much use in maintaining a reasonable lag in the standby database. The typical, or recommended value is 1800 (30 minutes). Extremely low values can result in frequent log switches, which could degrade performance; such values can also make the archiver process too busy to archive the continuously generated logs.
建议半个小时到1个小时切换一次，以下为了做实验测试，设置了60秒。

SQL> show parameter lagNAME                                 TYPE        VALUE------------------------------------ ----------- ------------------------------archive_lag_target                   integer     0client_result_cache_lag              big integer 3000plsql_ccflags                        stringSQL> alter system set archive_lag_target=60;  --单位秒System altered.SQL> show parameter archive_lag_target;NAME                                 TYPE        VALUE------------------------------------ ----------- ------------------------------archive_lag_target                   integer     60

SQL> select name,COMPLETION_TIME from v$archived_log where name is not null order by COMPLETION_TIME desc ;NAME                                                         COMPLETION_TIME------------------------------------------------------------ -------------------+DATADG/arch/log_1_406_961866198_585bafa7.arc                2018-01-25 12-04-59+DATADG/arch/log_1_405_961866198_585bafa7.arc                2018-01-25 12-03-59...................省略