As Claudio,I also highly suggest that you read this article.
http://www.west-wind.com/presentations/internetenabling/internetenabling.htm

It give some of the pro's and cons of how do handle some of what you are talking about.

For a quick thought I would have a nightly update of all the tables to each of the remote sites(automatically) and have say hourly updates of new tranactions set up to a ftp server, which then merges into the dbf at the server...
That at least what I would try to do..
Bob Lee






>Hi Bob,
>
>Tks yr reply,
>
>>Quite a few questions need to be answered by you, before you undertake such a process
>
>>1 What is your back end ? Dbfs - sql ?
>I will be using VFP6 database as back end. Dbfs.
>
>>2 What is your communication protocal? odbc ado ftp http ?
>I'm not sure which one is more robust and reliable? Pl guide.
>
>>3 How large is the data base are the clients' going to have a full copy ?
>The database consists of 112 tables. Of which around 15 will be continuously updated. This is an Order processing + Costing application. Which will updated by our remote site, and than uploaded to our main server, for review. Changes are possible at main server side, which needs to be updated at remote site as well.
>
>>4 what is being sent back to the server, New records or just updates or both?
>Both.
>
>>5 Have you worked out what to do if the same record is updated on the server, before the client updates it remotly.? who / or what record takes the override ?
>Not particularly, but the normal practice is to keep the latest one. Will be logging the date and time of modifications, and compare with the current data. If rejected, the remote server will be notified.
>
>I will be limiting the modifications to data at main server side, however can't avoid.
>
>>6 When you update the server, is a new copy of the dbf's going to be made avail for the remote user ?
>Yes. Thought the changes won't be big. Creating of record will only permitted to remote site.
>
>>
>>These are just a few questions which you need to consider as you work your way thought such a process. Most of these questions are not / programmer related, but more a business practice. Then you write your application based on the answers to the the requirments at hand.
>>
>>Once you know in your head, how it suppose to work, than coding it (at least for me becomes quite simple.) Break it down into smaller steps. Your answers are right there in front of you.
>
>Thanks for the encouraging sentences, please go through my answers and let me know what are the best practises, in terms of developing these types of applications.
>
>Cheers
>Shaishav
>
>>
>>
>>Bob Lee
>>
>>
>>
>>>I'm planning to develop a distributed application, which will periodically update the master database.
>>>
>>>That means, users will update their local database and later on the data will be synchronized with the master database on remote server.
>>>
>>>Can anyone guide me on the best practises on these type of development.
>>>
>>>TIA