Solr 6.0 and graph traversal support

One of the new features that are present in the recently released Solr 6.0 is the graph traversal query that allows us to work with graphs. Having a root set and relations between documents (like parent identifier of the document) we can use a single query to get multiple levels of joins in the same request. Let’s look at this new feature working both in old fashioned Solr master – slave as well as in SolrCloud.

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Switch Query Parser – quick look

The number of different query parsers in Solr was always an amusement for me. Can someone here say how many of them are currently available and say what are those? Anyway, in this entry we won’t be talking about all the query parsers available in Solr, but we will take a quick look at one of them – the SwitchQueryParser introduced in Solr 4.2.

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Do I have to look for maxBooleanClauses when using filters ?

One of the configuration variables we can find in the solrconfig.xml file is maxBooleanClauses, which specifies the maximum number of boolean clauses that can be combined in a single query. The question is, do I have to worry about it when using filters in Solr ? Let’s try to answer that question without getting into Lucene and Solr source code.

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Optimization – query result window size

Hereby I would like to start a small series of articles describing the elements of the optimization of Solr instances. At first glance I decided to describe the parameter that specifies the data fetch window size – the query result window size. Hopefully, this article will explain how to use this parameter, how to modify and adapt it to your needs.

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The scope of Solr faceting

Faceting is one of the ways to categorize the content found in the process of information retrieval. In case of Solr this is the division of set of documents on the basis of certain criteria: content of individual fields, queries or on the basis of compartments or dates. In today’s entry I will try to some scope on the possibility of using the faceting mechanism, both currently available in Solr 1.4.1, as well as what will be available in the future.

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6 deadly sins in the context of query

In my work related to Lucene and Solr I have seen various queries. While in the case of Lucene, developer usually knows what he/she wants to achieve and use more or less optimal solution, but when it comes to Solr it is not always like this. Solr is a product which could theoretically be used by everyone, both the person who knows Java, one that does not have a broad and specialized technical knowledge, as well as programmer. Precisely because of that Solr is a product which is easy to run and use it, at least when it comes to simple functionalities. I suppose, that is why not many people are worried about reading Solr wiki or at least review the mailing list. As a result, sooner or later people tend to make mistakes. Those errors arise from various shortcomings – lack of knowledge about Solr, lack of skills, lack of experience or simply a lack of time and tight deadlines. Today I would like to show some major mistakes when submitting queries to Solr and how to avoid those mistakes.

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Solr and PhraseQuery – phrase bonus in query stage

In the majority of system implementations I dealt with, sooner or later, there was a problem – search results tunning. One of the simplest ways to improve the search results quality was phrase boosting. Having the three most popular query parsers in Solr and the variety of parameters to control them I though it will be a good idea to check how they behave and how they affect performance.

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