Re: Dataguarad Real Time Apply

On Wed, 29 Aug 2007 14:19:28 -0700, joel garry <joel-garry_at_home.com> wrote:

>I have this vague memory of being in a user group presentation about
>this, which pointed out that the synchronous talking between lgwr on
>the primary and RFS on the standby (as show in figure 6.1 in the doc
>David alluded to) allows network latency to affect logging on the
>primary. Maybe it only applies to modes other than maximum
>performance mode. Maybe lack of performance doesn't have to come from
>slight amounts of lgwr overhead, but rather delays in talking to
>lgwr... or is a wait state overhead?

If using lgwr takes too much time Dataguard is automagically downgraded to Maximum Performance mode using ARCH. At least: this is the situation in 9iR2. Speaking from experience: I have a situation with insufficient bandwith. Yes, it keeps working, but statspack shows you are waiting on the standby for 75 percent of your time.

-- 
Sybrand Bakker
Senior Oracle DBA