If the time span or website (I assume you mean domain name) is a field
in your index then you can use result grouping.
Result grouping has impact on your query time and if you have a lot of
data you need to divide your data across multiple
indices and use distributed result grouping.
Martijn
On 2
I've never come across this GroupingCollector stuff before so know
nothing about it apart from looking at the javadocs and may be talking
nonsense, but here goes anyway.
group by time span/web site: it appears that it will group by single
values, not ranges, So should work fine by website. Just
