ARCHIVE_LAG_TARGET

Parameter type	Integer
Default value	0 (disabled)
Parameter class	Dynamic: ALTER SYSTEM
Range of values	0 or any integer in [60, 7200]
Oracle9i Real Application Clusters	Multiple instances should use the same value.

ARCHIVE_LAG_TARGET limits the amount of data that can be lost and effectively increases the availability of the standby database by forcing a log switch after a user-specified time period 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.

See Also: For more information about criteria for setting this parameter, see Oracle9i Data Guard Concepts and Administration