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12c R1测试环境
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