RE: Replication questions

From: Michael Fontana <>
Date: Tue, 18 Nov 2008 14:36:31 -0600 (CST)
Message-ID: <>

If your volume is as small as you suggest, you might get away with using the old "advanced replication" or "Multimaster replication" product. It's still a nuisance if you do large scale updates and can't control or unaware of their occurrence.

-----Original Message-----

From: [] On Behalf Of Bill Ferguson
Sent: Tuesday, November 18, 2008 2:15 PM To: oracle-l
Subject: Replication questions

Hi all,

This is an area I haven't delved much into, so I'm hopefully looking for a few real world examples.

My master database is here in Denver, CO, with an alternate in Reston, VA.

The (new) master in Denver is running 64-bit on Windows 2003 Server (also 64-bit). The alternate is running on 32-bit Windows 2003 Server. They both are setup to use the same character set as well.

We were using Shareplex (from Quest) for replication, but they don't have a version yet for 64-bit, and the licensing costs are rather steep. I am also a more-or-less one-man office, so simplicity is critical with all of my other duties (I'm currently working from home for free for the next month and half to use up my accrued Annual Leave, just so I can keep up with the workload).

Anyway, I've been tasked with determining alternative replication/backup options. The ones that come to mind are:

  1. Wait for the 64-bit version of Shareplex, and hope it works between 32-bit and 64-bit versions of Oracle.
  2. Streams
  3. Dataguard
  4. Nightly exports from 64-bit master, import into 32-bit alternate.
  5. Transportable tablespaces?

The big problem that immediately comes to mind is simply the 64-bit to 32-bit conversion. I'm thinking that will negate #4 as an option. It may produce problems with options #2-4 as well, but I don't know. I last tried Streams about 3 years ago, and it was a bear, requiring lots of baby-sitting.

Does anybody have any experience with any of these options between platforms? Will any of them work right away? I'm going to try and make some time later this week to experiment with the 64-bit export and 32-bit import to see how that works. The alternate can probably be safely one or two days out-of-sync without much critical data loss. It would be 'nice' to have them simultaneously synced all the time, but we can also forsee problems that way as well, where a 'problem' global change would get replicated right away across both systems, whereas with the export/import routine, there is at least a little lag time to notice problems before they are propagated. The export files themselves could also be archived, so if we ever had to, we go back to a certain date and import the table from an older export file.

The database is rather small, only around 84 GB, with little usage (at least right now). There's probably fewer than 3,000 data changes per day, and that would be an extremely high amount of updating. Once in a while we may do a 'batch' update, changing a field value or something, but not to often.



-- Received on Tue Nov 18 2008 - 14:36:31 CST

Original text of this message