On Fri, 2016-12-02 at 11:21 +0000, Markus Jelsma wrote: > Despite the number of actual results, queries with a very high > facet.limit are three to five times slower compared to much lower > values. For example, i have a query that returns roughly 19.000 facet > results. Queries with facet.limit=20000 return within 200 ms but > queries with facet.limit= 20 million return after around 800 ms. This > is in a cloud environment.
First all, requesting top.20M facet terms in a multi-node cloud is really not advisable as the transfer+merge overhead is huge. Have you considered streaming? > I vaguely remember an issue where Solr reserves the requested limit, I looked at both simple String faceting and numeric faceting in Solr. While there are pre-allocations of the structures involved, they both have build-in limiting, so the large performance difference that you are seeing is a bit strange. This was with the Solr 5.4 code that I happened to have open. Which version are you using? Just a thought: For plain search, specifying rows=20M is quite different from rows=20K, as that code does not have the same limiting as faceting. Are you perchance setting rows together with facet.limit? - Toke Eskildsen, State and University Library, Denmark
