Re: Questions for Oracle advanced replication

Shi,
Hi. I have answered your questions in the body of your message to the best of my abilities.

Shi yousong wrote:
>
> Hi,
>
> I am involved in a project to setup a replication infrastructure and
> plan to use the Row-Level async replication facility to implement a
> failover Oracle database infrastructure, so any change to the DB1 will
> be propagated to DB2 and vice versa. Here the questions are raised.
> What will happen if the connection between DB1 and DB2 is cut off?
> a. Say transaction A updates a table in DB1. Now can the transaction
> A be seen on DB1 when DB2 is not available? How about the resources
> occupied by transaction A ? released or still held on ?

  You mentioned that you are planning to set up 'async' replication. This means that even if DB2 is not available the replication jobs will be queued up and when your destination (DB2) is accessible it will push them according to the parameters specified by you.

> b. At the moment if DB1 and DB2 are identical to each other ?

        GOOD!!??!!
> c. After 2-3 hours, the connection is restored for example, can Oracle
> automatically make the 2 DB consistent again?
> From what I have experienced it does. You might have the db which is out of sync and then you will have to sync it (which is a bit of a pain) but you generally do not lose any data if thats what you are afraid of.

                                        Hope this helps.

                                                        Tapan H Trivedi
> Thanks in advance.
>
> Database Developer
> Sam Shi

Received on Tue Sep 28 1999 - 09:19:47 CDT