De Simone, Alessandro [alessandro.desim...@bvdinfo.com] wrote: > We have a performance issue ever since we stopped optimizing the index. We > are using Lucene 4.8 (jvm 32bits for searching, 64bits for indexing) on > Windows 2008R2.
How much RAM does your search machine have? > For instance, a search with (2 termQuery + 1 spanquery) x 6 fields made 143 > IO calls. Now with 16 segments we have 2432 IO calls and the search time is > really bad. [...] That sounds right. Although each segment is 1/16 of the full index size, the number of seeks per segment is not 1/16: Larger indexes require relatively fewer seeks. Think binary search and log(values_in_field), although that is highly simplified. > The size of the Index is ~24gb (14millions documents). No field are stored, > only indexed. Normally the penalty of running un-optimized is not that great, so it sounds like your machine cannot provide the I/O speed it needs (as opposed to having a great logistics overhead from the multiple segments). I am guessing that you are using spinning drives and that there is not much RAM in the machine? The easy solution is either to throw RAM at the problem or switch to SSD. - Toke Eskildsen --------------------------------------------------------------------- To unsubscribe, e-mail: java-user-unsubscr...@lucene.apache.org For additional commands, e-mail: java-user-h...@lucene.apache.org
