Hello,
We're on 11gR2 with active DataGuard replication between several RAC databases.
We've noticed that for many DBs the lag (checked with a select on v$dataguard_stats)
is fluctuating, growing up sometimes to more than an hour before reducing itself
all of a sudden to a few minutes or seconds, it changes all the time (I mean for a given
DB we don't keep a regular lag more or less constantly: it moves a lot).
Yet these DBs incur transactions (not many, but this is permanent) all the while so I
thought that the lag would never be bigger than, say, a few minutes...
How can you explain this behaviour ?
Thanks...
Regards,
Seb