Hi Chris, as always: "it depends". Generally I would reserve space of approximately the "original" index size. Most indexes that are continuously updated have an overhead by 40% for deleted documents. The remaining 60% are indeed used for merging. Please also keep in mind that if IndexReaders are open while merging, you may see not all used disk space from the directory listing, because some files that were merged but are still open in IndexReaders already disappeared from directory listing (deleted during merge), but still consume disk space (delete on last close POSIX semantics).
If you also "forceMerge" your index (you should never ever do this), you may temporarily need 3 times the index size. Uwe ----- Uwe Schindler Achterdiek 19, D-28357 Bremen http://www.thetaphi.de eMail: u...@thetaphi.de > -----Original Message----- > From: Chris Bamford [mailto:ch...@bammers.net] > Sent: Friday, March 3, 2017 7:24 PM > To: java-user@lucene.apache.org > Subject: Index size variation > > Hello > > I have observed that sometimes my index size temporarily increases by a > large amount, presumably while it it merges segments. > > Is there some documentation on this subject? I am trying to estimate total > disk space I'll need for a project. > > Thanks > > Chris > > > > > --------------------------------------------------------------------- > To unsubscribe, e-mail: java-user-unsubscr...@lucene.apache.org > For additional commands, e-mail: java-user-h...@lucene.apache.org --------------------------------------------------------------------- To unsubscribe, e-mail: java-user-unsubscr...@lucene.apache.org For additional commands, e-mail: java-user-h...@lucene.apache.org
