Hi, I would suggest to read: http://www.searchworkings.org/blog/-/blogs/380798
In general, if the index changes often, don't force merges. IndexWriter automatically merges to a suitable number of segments. Uwe Gili Nachum <gilinac...@gmail.com> schrieb: >Hi there Lucene samurai! > >*I was wondering how important is single segment merging for search >time >performance compared to a more modest merging goal like merging down to >just 4 segment. >* > >Currently my system merges every evening, it takes ~1-2 hours, and >invalidates the File-system cache. >What would happen if I'll reduce the merging target to just 4 segments? >e.g., When searching a term, does Lucene needs to visit each segment >(disk >seek operation) to access the relevant posting list? If not then what's >the >advantage of merging down segments (besides open files limit). > >*Was wondering if anyone has tested # of segments against search time >performance?* > >I should add I have ~10 indexes, at a total size of 50GB, and I use >mutli-index searcher to search over them (Lucene 3.0.3 - yeah it's old >I >know). The index is updated every 15min. > >Gili Nachum. -- Uwe Schindler H.-H.-Meier-Allee 63, 28213 Bremen http://www.thetaphi.de
