Does Ignition have a way of ‘sharing’ queries on a terminal server?
For example, we are using a terminal server with 10 clients. Each client has the same screen with the same 30 queries running every second. That equals up to 300 queries per second, even though all of the data is actually the same.
OPC works like this, right? If one client puts a tag in the tag scan list, everyone has it.
Currently, it doesn’t work that way. All queries have to run through the database. However, oft used queries, such as what you are describing should run through the db’s buffer, and not read from disk. So you have that going for you. 
That being said, I think that an SQLTag of a dataset type is slated for v7.8 according to this feedback thread.
I am alpha-testing a new module that provides this kind of caching for time-series database tables. And it works across all clients of a particular server, not just terminal server or mobile clients. Look for the announcement in a few weeks.
Great responses!
I’ll look for both solutions in the near future!
This has been announced as the Time Series Database Cache module and is available in the marketplace.