Solr LocalParams and Security

Local Parameters are often called as LocalParams. Using this we can “localize” information about an argument that is being sent to Solr through Solr query. its another way of adding…

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Using Solr and TikaOCR to search text inside an image.

Tesseract is probably the most accurate open source OCR engine available and with Apache Tika 1.7 you can now use the awesome Tesseract OCR parser within Tika!

Solr 5.x has support…

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Using Solr's ComplexPhraseQueryParser

ComplexPhraseQuery allows complex phrase query syntax e.g “canc* treat* “. It Performs multiple passes over Query text to parse any nested logic in PhraseQueries.

The first pass takes any PhraseQuery content…

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Measuring Search Relevance using NDCG

Normalized Discounted Cumulative Gain (NDCG) is popular method for measuring the quality of a set of search results. It asserts the following:

Very relevant results are more useful than somewhat relevant…

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Query Rescoring in Solr

Sometimes relevance requirements are very complex and creates performance issues during execution. There is a very nice feature Introduced in Solr 4.9 called “Query Reranking/Rescoring” (SOLR-6088) which allows us to…

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Understanding PhraseQuery and Slop in Solr

PhraseQuery in Lucene matches documents containing a particular sequence of terms. PhraseQuery uses positional information of the term that is stored in an index. 

The number of other words permitted between…

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