So far no answer from Sofiya. That's fair enough: My suggestions might have seemed random. Let me try to qualify them a bit.
What we have to work with is the redacted query q=<q expression>&fl=<full list of fields>&start=0&sort=<sort expression>&fq=<fq expression>&rows=24&version=2.2&wt=json and an earlier mention that sorting was complex. My suggestions were to try 1) Only request simple sorting by score If this improves performance substantially, we could try and see if sorting could be made more efficient: Reducing complexity, pre- calculating numbers etc. 2) Reduce rows to 0 3) Increase rows to 100 This measures one aspect of retrieval. If there is a big performance difference between these two, we can further probe if the problem is the number or size of fields - perhaps there is a ton of stored text, perhaps there is a bunch of DocValued fields? 4) Set fl=id only This is a variant of 2+3 to do a quick check if it is the resolving of specific field values that is the problem. If using fl=id speeds up substantially, the next step would be to add fields gradually until (hopefully) there is a sharp performance decrease. - Toke Eskildsen, Royal Danish Library
