Unanswered: Size of Distribution Database-Replication
We are setting up Merge replication and size of the database is
85 GB. How much disk size is feasible to keep for distribution Database.
Is there any % basis (SIZE) for Distribution DB according to the size of the database?
Is it feasible to keep seperate server for Distribution Server or keeping
Publisher and distributor on same same.
The size of Distribution database depends NOT on the size your replicated database, but on the volume of transactions at the peak time. You can take a guess and let it grow by itself for a while. Over time it will grow to its optimal size. Just don't shrink it, it's a bad idea.
There's goods and bads about having a different machine to run the Distributor. Of course, if your network pineline is large enough and the processing power of the machines which runs the Distributor is powerful enough, then do it. Remember, the publisher will publish data onto the distributor, and that process alone needs network speed and I/O. Running both Publisher and Distributor on the same machine will be a logical choice if your network pineline is not large enough and the machine you have for distributing is slower.
What is retention period for replication? Default is 14 days. It means that distribution database keeps history of changes for 14 days. If you change it to 2-3 days - size of database could be dramatically decreased.