Replication technology suggestion

Hi,

We are developing an application using Oracle database. The application will be deployed at multiple sites. Here is what we would like to do:

1. Replicate data from each databases to a single central secondary site. It will be many to one replication meaning many databases will be sending the data to a single database. This secondary site, call it as backup site is used as DR solution.
2. In case any primary database is down we would like to use the secondary database to become primary. We are not planning 24 by 7 solution. But in case of long outage we would like to serve from secondary site if possible.
3. Secondary site may be a primary site for some deployment while serving as a backup site for other deployments.

Currently I am evaluating using MV or streams. We haven't used Data guard so far. Will only consider if the purpose can't be achieved by MV or Streams.

Please suggest!

Thanks

Sandeep

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