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
