On Mon, 2015-10-12 at 10:05 +0200, Jan Høydahl wrote: > What you do when you call optimize is to force Lucene to merge all > those 35M docs into ONE SINGLE index segment. You get better HW > utilization if you let Lucene/Solr automatically handle merging, > meaning you’ll have around 10 smaller segments that are faster to > search across than one huge segment.
As individual Lucene/Solr shard searches are very much single threaded, the single segment version should be faster. Have you observed otherwise? Optimization is a fine feature if ones workflow is batch oriented with sufficiently long pauses between index updates. Nightly index updates with few active users at that time could be an example. - Toke Eskildsen, State and University Library, Denmark
