Re: Question On Data Guard And Database Refreshes
From: Jeremy Schneider <jeremy.schneider_at_ardentperf.com>
Date: Fri, 6 Jun 2014 17:06:08 -0500
Message-Id: <D299FCF2-2347-40A6-989D-2A2E0FE0CA55_at_ardentperf.com>
I've been doing a lot with rman recently. Data pump is probably the simplest thing since it's all logged and the standby automatically stays in sync. But if you're doing a large database (hundreds of GBs or some TBs) then this may not work. In my experience, building the standby over the network from the active primary only works for smaller databases - as far as I can tell it doesn't do any compression or other optimization of the data sent over the wire and takes forever. For large databases I've had the best luck with running a one-off rman backup, copying the files across with rsync, then doing a restore on the far side. Have to manage logs carefully since you'll need them all to catch up the standby. But I've managed to build a multi-TB standby this way over a not-so-great WAN link. Took a few days. :) Sounds tedious but it's not bad at all once you've done it a few times. If this won't work then the only other technique I know is driving or overnighting hard drives.
Date: Fri, 6 Jun 2014 17:06:08 -0500
Message-Id: <D299FCF2-2347-40A6-989D-2A2E0FE0CA55_at_ardentperf.com>
I've been doing a lot with rman recently. Data pump is probably the simplest thing since it's all logged and the standby automatically stays in sync. But if you're doing a large database (hundreds of GBs or some TBs) then this may not work. In my experience, building the standby over the network from the active primary only works for smaller databases - as far as I can tell it doesn't do any compression or other optimization of the data sent over the wire and takes forever. For large databases I've had the best luck with running a one-off rman backup, copying the files across with rsync, then doing a restore on the far side. Have to manage logs carefully since you'll need them all to catch up the standby. But I've managed to build a multi-TB standby this way over a not-so-great WAN link. Took a few days. :) Sounds tedious but it's not bad at all once you've done it a few times. If this won't work then the only other technique I know is driving or overnighting hard drives.
Always interested to hear what others think to!
-Jeremy
-- http://about.me/jeremy_schneider Sent from my iPhoneReceived on Sat Jun 07 2014 - 00:06:08 CEST
> On Jun 6, 2014, at 2:30 PM, Scott Canaan <srcdco_at_rit.edu> wrote:
>
> I did try this a couple of times and got errors and it would never complete. It might have been due to the network.
>
> Scott Canaan ’88 (srcdco_at_rit.edu)
> (585) 475-7886 – work (585) 339-8659 – cell
> “Life is like a sewer, what you get out of it depends on what you put into it.” – Tom Lehrer
>
> From: Kenny Payton [mailto:k3nnyp_at_gmail.com]
> Sent: Friday, June 06, 2014 3:28 PM
> To: Scott Canaan
> Cc: oracle-l_at_freelists.org
> Subject: RE: Question On Data Guard And Database Refreshes
>
> I got the idea originally, as well as example scripts, from the Oracle Press book Oracle Data Guard 11g.
>
> It doesn't require previous RMAN backups so you don't have to worry about not using it now. Essentially it's duplicating the database across the network using RMAN.
>
> Just be careful not to overrun your network connections if you're not using separate and dedicated network interfaces for data guard.
>
> Kenny
>
> On Jun 6, 2014 3:19 PM, "Scott Canaan" <srcdco_at_rit.edu> wrote:
> Yes, that might work. We don’t use RMAN now because it doesn’t work nice with our current backup system. That’s why we aren’t using it for the refresh.
>
> Scott Canaan ’88 (srcdco_at_rit.edu)
> (585) 475-7886 – work (585) 339-8659 – cell
> “Life is like a sewer, what you get out of it depends on what you put into it.” – Tom Lehrer
>
> From: Kenny Payton [mailto:k3nnyp_at_gmail.com]
> Sent: Friday, June 06, 2014 3:19 PM
> To: Scott Canaan
> Cc: oracle-l_at_freelists.org
> Subject: Re: Question On Data Guard And Database Refreshes
>
> If you're refreshing a significant part of sizeable databases you might find it more efficient to automate RMAN duplicate across the wire.
>
> Kenny
>
> On Jun 6, 2014 1:36 PM, "Scott Canaan" <srcdco_at_rit.edu> wrote:
> We have dived into the world of Data Guard and have it working nicely. Periodically, we get requests to refresh a test database from production to get “up-to-date” data in test. If both production and test are Data Guarded, what is the best way to do the refresh? We would like to not to have to rebuild the test secondary database if at all possible. We don’t use RMAN for backups. We are looking at using Data Pump between production and test and letting Data Guard update the secondary from there.
>
> Is there a better way, without purchasing a tool?
>
> We are using Oracle 11.2.0.3 on Red Hat Linux.
>
> Thank you,
>
> Scott Canaan ’88 (srcdco_at_rit.edu)
> (585) 475-7886 – work (585) 339-8659 – cell
> “Life is like a sewer, what you get out of it depends on what you put into it.” – Tom Lehrer
>
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