Hello! On Monday 05 April 2010 16:47:48 Simon Slavin wrote: > Do you have an idea when a tree index should be used, and when a hash index > should be used ? Will you use both all the time, or allow the user to select > which one to use ?
See tests here: http://geomapx.blogspot.com/2010/04/sqlite-index-degradation-tests.html and http://geomapx.blogspot.com/2009/11/degradation-of-indexing-speed.html Now FTS3 can be used as effective hash index but with big overhead and difficulties for developers. FTS3 work nice with billions of unique values in big tables (a few hundred millions records) with constant speed. The b-tree index is required then we selecting range of indexed values and has good performance for 1000 or less unique values in indexed field. All other RDMS have hash indices because these required in many applications. Best regards, Alexey Pechnikov. http://pechnikov.tel/ _______________________________________________ sqlite-users mailing list sqlite-users@sqlite.org http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users
