Hey all. I ran into an issue recently. I have a rather large index and in my application I had defined values for the "pf" parameter, but I had commented it out years ago not really knowing why I did it. Obviously the point of the pf helps rank fields higher if they are in close proximity, and this is good if you do a text search but want a boost on the "title" for example.
So I un-commented out the line, to enable it to go against 6 important fields. Afterwards through monitoring performance I noticed that my searches were taking roughly 50% to 100% (2x!) longer, and it started at the exact time I committed that change, 1:40 pm, qtimes below in a 15 minute average cycle with the start time listed. What im assuming is happening behind the scenes is solr is doing an auxiliary search on the defined fields as field1:"word word word"~n+x field2:"word word word"~n+x field3:"word word word"~n+x where n is the number of words and x is whatever arbitrary number. obviously this adds a LOT to the search on the back end if I understand the functionality correctly. is there any recommendation to get roughly my old speeds back without a full re-index to a new "metadata" type field BUT still keep the features of the pf parameter? Also using a qf parameter. set up: solr 5.x 400gb+ index 16mm docs, 24mm with deletes. 2TB SSD, 24 cores, 148gb ram, 50gb heap size, about 30,000 searches a day. Thanks! -Dave no pf: | 2017-03-29 13:00:03 | 355.1961 | | 2017-03-29 13:15:05 | 277.5479 | | 2017-03-29 13:30:03 | 235.2263 | | 2017-03-29 13:45:01 | 398.5000 | | 2017-03-29 14:00:00 | 371.3048 | | 2017-03-29 14:15:05 | 373.9901 | | 2017-03-29 14:30:00 | 401.2474 | | 2017-03-29 14:45:01 | 358.0344 | | 2017-03-29 15:00:00 | 404.0234 | changed pf at 140pm: | 2017-03-30 13:00:00 | 270.4377 | | 2017-03-30 13:15:00 | 397.9880 | | 2017-03-30 13:30:00 | 474.8985 | | 2017-03-30 13:45:02 | 1082.0114 | | 2017-03-30 14:00:03 | 821.8152 | | 2017-03-30 14:15:04 | 1034.8388 | | 2017-03-30 14:30:00 | 1405.7792 | | 2017-03-30 14:45:01 | 1200.1488 | | 2017-03-30 15:00:00 | 694.4559 |
