So that would require Lucene to dynamically/periodically check field values and their frequencies and switch from a regular inverted index to a bitmap index or just create an additional bitmap index for those fields and their values?
Otis ----- Original Message ---- > From: Michael McCandless <luc...@mikemccandless.com> > To: java-dev@lucene.apache.org > Sent: Friday, February 27, 2009 4:41:32 PM > Subject: Re: Bitmap index > > > I think with column stride fields we should use Bitmap Index to represent > fields > that have few values across many docs. > > Mike > > Uwe Schindler wrote: > > > In my opinion, we currently use some type of bitmap index with our filters. > > OpenBitSet and SortedVIntList used in filters can be seen as bitmap indexes > > specifying if a document is a hit of the filter or not. Maybe we can use the > > compression technology mentioned in this Wikipedia article to further > > optimize filters and their DocIdSetIterators. > > > > In my opinion, the real use of bitmap indexes is data warehousing, when > > low-cardinality-columns are used. We are using Sybase IQ (a column oriented > > database) that has heavy usage of bitmap indexes (a variation of them are > > called LF - low-fast indexes there). > > > > Uwe > > > > ----- > > Uwe Schindler > > H.-H.-Meier-Allee 63, D-28213 Bremen > > http://www.thetaphi.de > > eMail: u...@thetaphi.de > > > >> -----Original Message----- > >> From: Otis Gospodnetic [mailto:otis_gospodne...@yahoo.com] > >> Sent: Friday, February 27, 2009 9:33 PM > >> To: java-dev@lucene.apache.org > >> Subject: Bitmap index > >> > >> > >> Hi, > >> > >> I've had http://en.wikipedia.org/wiki/Bitmap_index open in my browser for > >> weeks, thinking I'd bring it up here -- would a bitmap index make sense > >> anywhere in Lucene (or perhaps Solr)? > >> > >> Otis > >> > >> --------------------------------------------------------------------- > >> To unsubscribe, e-mail: java-dev-unsubscr...@lucene.apache.org > >> For additional commands, e-mail: java-dev-h...@lucene.apache.org > > > > > > > > --------------------------------------------------------------------- > > To unsubscribe, e-mail: java-dev-unsubscr...@lucene.apache.org > > For additional commands, e-mail: java-dev-h...@lucene.apache.org > > > > > --------------------------------------------------------------------- > To unsubscribe, e-mail: java-dev-unsubscr...@lucene.apache.org > For additional commands, e-mail: java-dev-h...@lucene.apache.org --------------------------------------------------------------------- To unsubscribe, e-mail: java-dev-unsubscr...@lucene.apache.org For additional commands, e-mail: java-dev-h...@lucene.apache.org
