what sort of limit? number of tags? number of event per tag? minimum time between events? max time between events?
The answer for all of these is really ‘It depends’.
It depends on how fast your hardware is, how much disk space you have to store data, how good your selected database is at storing lots of data, how you partition the data,…
My experience with PostgreSQL has been that it can handle about 5,000,000 rows per table and then it starts slowing down.
Ignition does not impose limits so it really does depends and you have to trial it and see.