That's indeed an alternative. Moreover, I have heard (not measured/comparered myself) from people who tried both MM and tmpfs approach that the former has some overhead.
Otis -- Sematext -- http://sematext.com/ -- Lucene - Solr - Nutch ----- Original Message ---- > From: Anshum <ansh...@gmail.com> > To: java-user@lucene.apache.org; paul_t...@fastmail.fm > Sent: Tuesday, March 24, 2009 6:42:58 AM > Subject: Re: Can you create a RAM index from a file index > > Hi Paul, > > Going by what you've conveyed here, I'd assume that you have more than some > data. You could either go ahead with Ian's way which is the suggested one(as > far as lucene implementation is concerned) but It'd not be possible if > you're index is greater than 2 Gigs and you are not running the 64 bit > version of JVM (as your JVM could not use more than 2Gigs of RAM otherwise). > The other workaround that I've tried successfully is by creating a tmpfs > partition and copying your index onto that tmpfs partition. This would also > mean that you'd need almost the same amount of 'free' ram to copy the index > onto the RAM. > You could then open your reader in the regular fashion straight off the RAM > based tmpfs. > You could also go through the archives for suggestions. > -- > Anshum Gupta > Naukri Labs! > http://ai-cafe.blogspot.com > > The facts expressed here belong to everybody, the opinions to me. The > distinction is yours to draw............ > > > On Tue, Mar 24, 2009 at 2:12 PM, Paul Taylor wrote: > > > Hi > > > > Ive built some file based indexes based on data in a database, and it took > > quite some time. > > I am interested in trying to use RAM based indexes instead of file based > > indexes to compare search performance but its going to take some time to > > rebuild the index from the original database, isnt it possible to rebuild > > the index from the file based index ? > > How big is a RAM index compared to File based index, I assumming its > > slightly smaller because no files are created ? > > > > thanks Paul > > > > --------------------------------------------------------------------- > > 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
