Good afternoon Ilkka and welcome back!
This is a great question.
The short answer is that the only limitation is what your server is able to handle.
In other words, the ability of performing queries successfully will depend on:
- The type of hosting plan you have (shared vs VPS vs dedicated)
- Your server settings and features(php version, Database size, execution time, memory limits, etc..)
- The amount of traffic on your server at the time of the import
So the short answer is that normally these numbers should be fine provided your server can handle it.
With that in mind, you absolutely have the right idea. If it looks like the import results are fishy, you might want to break the import down in several smaller imports.
Best regards,
Geoff B.