This is more of viability question.

I have a database running at a site.
It needs to be used at 2 sites (continuously), in use all the time.
The data needs to be the same at both sites, but the connection is between sites is running
an a standard ADSL line with a VPN.
Having the data on one site and referenced from the other real time is a big no no for speed on the remote site.

Is it really viable to mirror the databases on the two sites and keep them synchronised?
How often could they realistically be synchronized if it is viable
and what are the implications bearing in mind that changes and additions would be being made on both,
and that they would be in fairly continuous use.

It has been requested for maybe every 10 minutes to which I said (SILLY).
Am I correct here?

Any suggestions?