Solr 4.10 and Heliosearch .07 have added a terms query (or terms filter) to more efficiently match many terms in a single field. A large number of terms are often useful for things like access control lists or security filters. Previously, the only way to do this was a large […]
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The filter caching features in Solr allow for precise control over how filter queries are handled in order to maximize performance. Solr has the ability to specify if a filter is cached, specify the order filters are evaluated, and specify post filtering. Solr Filter Queries Adding a filter expressed as […]
Solr Filter Caching
Solr 4.8 has been released. Here’s an overview of how to use some of the new features. Also see Solr download links and upcoming features of the next Solr release. Complex Phrase Queries The complexphrase query parser can produce phrase queries with embedded wildcards and boolean queries. It works via […]
Solr 4.8 Features
nCache Heliosearch has a new replacement for the Lucene FieldCache currently used by Solr for sorting, faceting, and function queries. Introducing nCache (n is for “native”): nCache has Off-Heap Data-structures, just like the Off-Heap Filters to lower garbage collection pauses and GC overhead. nCache is a managed cache, meaning […]
nCache: Heliosearch/Solr Off-Heap FieldCache
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Off-Heap Native Filters is the first feature we added to Heliosearch, a new open source project designed to bring Solr performance to the next level. Big JVM heaps can be Big Trouble JVMs have never been good at dealing with large heaps. Large heaps mean lots of garbage collection work, […]
Heliosearch/Solr Off-Heap Filters
The filter caching features in Solr allow for precise control over how filter queries are handled in order to maximize performance. Solr has the ability to specify if a filter is cached, specify the order filters are evaluated, and specify post filtering. Solr Filter Queries Adding a filter expressed as […]
Advanced Filter Caching in Solr
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 commit (or a new Near Real Time softCommit) needs to […]
Solr’s Realtime Get
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) returns the number of times the term appears in the […]
Solr relevancy function queries
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 bug fixes, performance improvements, and feature enhancements. You’ll need a […]
Solr Result Grouping / Field Collapsing Improvements
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 faceted search, except instead of just getting a count, you […]