Replication strategy

We are going to run an central database that will replicate some of it's tables to three local databases around the country via an ISDN connection. Now, as I understand it, a refresh will query the central database, so I thought it might be a bad idea to let all three local databases run a refresh at the same moment. On the other hand when they are running synchronous, thay may benefit from data that is already cached.

As the refresh is not really time critical, I want to refresh the first site every hour, the second one 10 minutes before every half hour and the third one 10 minutes after every half hour. This will spread the load on the central database. Also, I do not want to replicate during the night and on sundays.

I think that using the automatic refresh groups from Oracle will be a bit awkward, given the specific times I want to run a refresh, and the times I do not want to run a refresh. The only other option, I think, will be to run an SQL script from the crontab.

My question is: does anybody out there have any additional thoughts, ideas, concepts or experience with the above? Any additional problems that I may hit when we go live?

Thanks
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Jan
pantah_at_commonsense.a2000.nl
(replace "commonsense" with "speed" to reply) Received on Wed Dec 16 1998 - 15:06:51 CST