On Sun, 2019-09-08 at 21:10 +0200, Günter Hipler wrote: > I have seen you have done a lot of work at the end of version 7 for > version 8 but was not sure if it is related to this issue.
It is directly related to DocValues, but it is unclear if that is Russell's challenge. Our setup is at the far end with 300M docs / 900GB segments. With Solr 7, performance dropped with a factor 10 for standard searches (as we used populated documents from DocValues instead of Stored) and a factor 100 for worst-case exports. Long story short * Solr 4-6 has random access DocValues * Solr 7 has iterator based (all previous blocks must be visited to get to the block containing the needed value) * Solr 8 has iterator based with skip lists (go directly to the needed block) Looking back in the list, I see that you had performance problems with faceting on Solr 6 too. I'll make a note to read up on that and respond in that thread, to avoid hi-jacking this one. It probably won't be this week as Real Work is heating up. - Toke Eskildsen, Royal Danish Library
