Solr has been able to slurp in CSV for quite some time, and now I’ve finally got around to adding the ability to output query results in CSV also. The output format matches what the CSV loader can slurp. Adding a simple wt=csv to a query request will cause the […]

CSV output for Solr


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 specifying the frange query type.  Here’s an example of a […]

Ranges over Functions in Solr 1.4


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 are more efficiently applied to the query during a search. […]

Filtered query performance increases for Solr 1.4



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 could delete a document at any time, the IndexReader.isDeleted() call […]

Solr scalability improvements


Having performance issues with Solr’s faceted search and certain types of fields?  Help has arrived in the form of a new Solr faceting algorithm!  This new faceting implementation dramatically improves the performance of faceted search, making it suitable for a much wider range of applications. The existing multivalued field faceting […]

Solr Faceted Search Performance Improvements


I was surprised to discovered that there isn’t a good cross-platform hash function defined for strings. MD5, SHA, FVN, etc, all define hash functions over bytes, meaning that it’s under-specified for strings. So I set out to create a standard 32 bit string hash that would be well defined for […]

lookup3ycs : a standard high performance string hash



A new chapter in Solr scalability has been opened with the addition of distributed search! http://wiki.apache.org/solr/DistributedSearch Distributed Search splits an index into multiple shards, and queries across all the shards, combining the results and presenting a single merged response that looks like it came from a single server. Solr’s current […]

Distributed Search for Solr


I’ll be giving a Solr presentation Nov 8th in Berlin, titled “Add Powerful Full Text Search to Your Web App with Solr“. Should be fun, just wish I had more free time while in Berlin…

Solr at Web 2.0 Expo Berlin