Background I needed a really good hash function for the distributed indexing we’re implementing for Solr. Since it will be used for partitioning documents, it needed to be really high quality (well distributed) since we don’t want uneven shards. It … Continued
Solr took another step toward increasing it’s NoSQL datastore capabilities, with the addition of realtime get. Background As readers probably know, Lucene/Solr search works off of point-in-time snapshots of the index. After changes have been made to the index, a … Continued
Lucene’s default ranking function uses factors such as tf, idf, and norm to help calculate relevancy scores. Solr has now exposed these factors as function queries. docfreq(field,term) returns the number of documents that contain the term in the field. termfreq(field,term) … Continued
I previously introduced Solr’s Result Grouping, also called Field Collapsing, that limits the number of documents shown for each “group”, normally defined as the unique values in a field or function query. Since then, there have been a number of … Continued
Solr has been able to produce JSON results for a long time, by adding wt=json to any query. A new capability has recently been added to allow indexing in JSON, as well as issuing other update commands such as deletes … Continued
Result Grouping, also called Field Collapsing, has been committed to Solr! This functionality limits the number of documents for each “group”, usually defined by the unique values in a field (just like field faceting). You can think of it like … Continued
Solr 1.4 contains a new feature that allows range queries or range filters over arbitrary functions. It’s implemented as a standard Solr QParser plugin, and thus easily available for use any place that accepts the standard Solr Query Syntax by … Continued
One of the many performance improvements in the upcoming Solr 1.4 release involves improved filtering performance. Solr 1.4 filters are both faster (anywhere from 30% to 80% faster to calculate intersections, depending on configuration), take less memory (40% smaller), and … Continued
With CPU cores constantly increasing, there has been some major work done in Lucene/Solr to increase the scalability under multi-threaded load. Read-only IndexReaders One bottleneck was synchronization around the checking of deleted docs in a Lucene IndexReader. Since another thread … Continued
