Re: Retrieving information updated/added/deleted

Stef wrote:

> Hello,
>
> We are working on Oracle 8i ( 8.1.7 ).
>
> We would like to retrieve quickly all the information ( structure and data )
> modified since a short time ... This is for synchronisation between 2
> databases ...
>
> What we have is :
> - DB1 : Production Database that is often modified by users.
> - DB2 : Mirror Database that contains the META DATA of the DB1 and the
> data also.
>
> The DB1 has many records ( more than 30 millions records in the biggest
> table - Insurance domain - with maybe some thousands modifications a day )
> and DB2 has to be refreshed every 2 hours. How to list all the modified
> information from DB1 when DB2 is refreshing.
>
> One of the solution we tried was putting a trigger on all the tables "After
> Insert", "After Update" that insert on a table RECENT_MODIF but this is
> really time consuming.
>
> I know all the modification are stored in the redo logs, but reading them is
> pretty complex...
>
> Would you know any other way to do such ?
>
> As the DB1 is huge, if I put a flag on that for retrieving quickly all the
> modified information, it will be so long to query on that, and, if we put an
> index on that column, it will be more time consumming for the production ...
>
> Thanks in advance,
>
> Regards.
>
> Stef

You don't need to "read" the redo logs. You can let Oracle restore from them. Go to http://tahiti.oracle.com and look up "STANDBY DATABASE AND REDO".

I would also look up "REPLICATION".

Daniel Morgan Received on Fri Dec 06 2002 - 10:34:55 CST