New Server Sharing Old Historian Database

Hey all! I'm getting ready to upgrade my Ignition server's hardware to a new machine and I have a few questions about handling the SQL database with our Historian data in it.

I plan on running both servers in parallel for a bit to get the new one set up and validated before retiring the old one. Can they both write historical data to the same SQL database if both servers will have duplicate tag names until the new server is commissioned and the old one retired?

For example, when something like a chart queries historical data for a tag named "Tag A" will it return historical data logged by both servers that have a tag named "Tag A" and combine them, or will "Tag A on Server A" and "Tag A on Server B" be two separate things to query? Is there a way to maintain consistency of Historical data in the transition from one server to another one?

I'd like to avoid creating a new database and breaking a relationship between tags of the same name on both servers if possible, since we have a lot of data analyst type staff that have their own scripts and Excel sheets and whatnot that query the Historian database directly to pull production data and it would really complicate things for them to have to modify all of that because all data after "cutover date and time" is now in a different database and tags with the same name have different ids and such.

Sorry this is kind of long winded, hopefully I explained well enough what I'm trying to do!

The gateway name is part of the metadata (in the sqlth_drv table) used to manage a given database's tag history tables. So as long as the two servers have unique names, the data will be separate.

Tag History browse components should show both hierarchies for you to pick from, unless you constrain their start point.

https://docs.inductiveautomation.com/display/DOC81/Ignition+Database+Table+Reference#IgnitionDatabaseTableReference-sqlth_drv