Getting Document by ordinal number

Our Documents have a timestamp field and query results are ordered by time.
Is it possible to get a Document by its ordinal number in the query result instead of getting it by exact timestamp
(timestamps may fluctuate) or reading the whole result set into memory for iteration?

_id does not work for me as it is auto-generated.



I'm not quiet sure I understand the question, but if you are trying to get only the Nth document in your query result, this sounds like you can use the from/size parameters. Make sure to read about the dangers of and cost of Deep Pagination before using this for large N.
In case I misunderstood the question, maybe you can rephrase it a bit and give an example of what you are trying to do.