solr delta import handler timestamp not specific enough

solr delta import handler timestamp not specific enough

I am new to solr and I have a quite basic question about delta-imports. I
have several new records by second in my mySQL DB. So when I start an
import at second x it is very possible, that I will get some new records
in the DB at the very same second after starting the import, but the next
time when I start a delta-import it will check the "last_index_time" in
dadaaimport.properties and will import all the records changed after this
second x. So I will lose all records which have been changed in second x
after starting the last import. And if I am right, it would be same issue
even if it is possible to cahange the timestamp from seconds to e.g.
milliseconds. The timewindow would be smaller, the amount of lost records
would be smaller, but the problem itself would still be there.
I have not found any mention of this issue in the tutorials or anywhere
else for that matter. Am I the first one who deals with several records
per second, or do i miss something else?
Many thanks in Advance!