12c archive_lag_targe forced log switching

12c R1 test environment

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.

It is recommended to switch from half an hour to one hour. Below, 60 seconds are set for experimental testing.

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 -- System altered.SQL > show parameter archive_lag_target per second NAME TYPE VALUE---archive_lag_target integer 60SQL > 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. Omit