RE: Best practice for Dataguard in 10g?

From: Vishal Gupta <vishal_at_vishalgupta.com>
Date: Sun, 6 Sep 2009 13:45:44 +0100
Message-ID: <787DD2F284E39D4FA3C2ABD2DAF1AB2D110D4C_at_MAIL.vishalgupta.co.uk>



Nuno,

As you are planning to run in maximum performance mode, even if you use LGWR for redo log shipping. If there is too much redo generation at any point in time which your network is not able to cope with, then log shipping will switch from LGWR to ARC automatically. And it will revert back to LGWR automatically when it catches up with latest redo generation.

So using LGWR should not be a problem for redo log shipping.

But if you are generating 500GB/day or 355MB/min on average. Then depending on your redo log size and log switching frequency. Using ARCH will also not harm you. It depends on how much data you are willing to use in case of primary DW failure. And when you can regenerate missed/lost data from your OLTP.

There will be *some* data loss even by using LGWR unless you are using SYNC and AFFIRM options, which you would not want to use to protect against hanging primary database, which will occur during network failure prevent redo log transfer.

Regards,
Vishal Gupta

--
http://www.freelists.org/webpage/oracle-l
Received on Sun Sep 06 2009 - 07:45:44 CDT

Original text of this message