Yeah, as mentioned, UpgradeIndexMergePolicy is easiest to customize to do that: You only have to override shouldUpgradeSegment() and return true for the segment to be merged, false otherwise. After that call forceMerge(1) to trigger the merge (1 does mean nothing, its just needed).
----- Uwe Schindler H.-H.-Meier-Allee 63, D-28213 Bremen http://www.thetaphi.de eMail: u...@thetaphi.de > -----Original Message----- > From: Michael McCandless [mailto:luc...@mikemccandless.com] > Sent: Friday, February 21, 2014 6:31 PM > To: Lucene Users > Subject: Re: Single segment merge in lucene possible? > > A custom MergePolicy can also select single-segment merges. > > Mike McCandless > > http://blog.mikemccandless.com > > > On Fri, Feb 21, 2014 at 9:53 AM, Uwe Schindler <u...@thetaphi.de> wrote: > > Hi, > > > > There are two possibilities: > > > > (1) Use IndexWriter.addIndexes(IndexReader) and copy the old index to a > new one. This will merge everything into one segment. > > > > (2) Use IndexUpgrader and override the method that determines if an > index segment is outdated. If you only return true for the segment that > needs to be merged to itself, and later start the upgrade process, it will > exactly do what you want. > > > > This is more or less a copypaste of the example in: > > > http://lucene.apache.org/core/4_6_0/core/org/apache/lucene/index/Upgra > > deIndexMergePolicy.html You just have to (anonymously) subclass > > UpgradeIndexMergePolicy and return true from "protected boolean > shouldUpgradeSegment(SegmentCommitInfo si)" only for the segment to > be merged. By default this returns true for segments that are written by > older Lucene versions. > > > > Uwe > > > > ----- > > Uwe Schindler > > H.-H.-Meier-Allee 63, D-28213 Bremen > > http://www.thetaphi.de > > eMail: u...@thetaphi.de > > > > > >> -----Original Message----- > >> From: Ravikumar Govindarajan > >> [mailto:ravikumar.govindara...@gmail.com] > >> Sent: Friday, February 21, 2014 3:24 PM > >> To: java-user@lucene.apache.org > >> Subject: Single segment merge in lucene possible? > >> > >> Hi, > >> > >> Is it possible to merge a single segment all by itself, may be just > >> accounting for deletes alone? > >> > >> This is needed so as to solve certain data-locality issues we face in > >> a custom implementation of Directory API. > >> > >> -- > >> Ravi > > > > > > --------------------------------------------------------------------- > > 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 --------------------------------------------------------------------- To unsubscribe, e-mail: java-user-unsubscr...@lucene.apache.org For additional commands, e-mail: java-user-h...@lucene.apache.org
