Using Luke with Lucene 8.7.0 to browse Elasticsearch 7.10.2 indices. In the Luke UI, I don't see anywhere that indicates the english/text name of the Elasticsearch index being browsed. Is this available anywhere? The folder name representation of the indices are guids, so it's difficult to understand which index I'm looking at.
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as you know, there are different technique to index documents for search engines.
such as inverted index, Distributed Dynamic Indexing, Semantic Indexing, NGram Indexing, Context Indexing, Big Data, Multilingual Indexing and so on.
I am working with Solr now. I wonder which techniques does Solr use to index documents and how does Solr (or Lucene) use these techniques?
First - this is a very wide area and most of the terms you're listing isn't index types. They describe product features (or buzzwords) that could be supported regardless of how the index is built behind the scene.
Solr uses Lucene - which at the core is an inverted index.
The index stores statistics about terms in order to make term-based search more efficient. Lucene's index falls into the family of indexes known as an inverted index. This is because it can list, for a term, the documents that contain it. This is the inverse of the natural relationship, in which documents list terms.
There is also many support structures in place to make Lucene even more efficient for certain queries and features. On such feature is the DocValues support - which can be described as a column oriented store with document -> term mappings to speed up things like faceting.
You can see most of these support features in the Codecs API Doc for Lucene 6.3.0. As it's quite a large list, I'll leave it out from the comment itself.
To answer which techniques - Under the hood , Solr uses Lucene APIs and Lucene indexing technique is - Inverted Indexing. Solr is simply a complete application with infrastructure wrapper but underlying document indexing technique is the one provided by Lucene APIs.
How does Solr (or Lucene) use these techniques?
Here is a nice overview of Lucene indexing for beginners. Its just a very simplistic overview but explains the basics.
Since Solr is a product, most of its available documentations are functional ones ( not explaining actual indexing techniques etc) and since raw usage of Lucene is minimal, Lucene documentation is not up to the mark so most of the time, one needs to dig Lucene code or API documentation to understand working of Lucene.
Hope it helps !!
I am using grails searchable plugin. It creates index files on a given location. Is there any way in searchable plugin to create Lucene index in a database?
Generally, no.
You can probably attempt to implement your own format but this would require a lot of effort.
I am no expert in Lucene, but I know that it is optimized to offer fast search over the filesystem. So it would be theoretically possible to build a Lucene index over the database, but the main feature of lucene (being a VERY fast search engine) would be lost.
As a point of interest, Compass supported storage of a Lucene index in a database, using a JdbcDirectory. This was, as far as I can figure, just a bad idea.
Compass, by the way, is now defunct, having been replaced by ElasticSearch.
I have a system that uses lucene. Now for a few reasons I would like to add a distributed search feature over it.
The question is can I use the existing lucene index created by the IndexWriter of lucene, for searching with elastic search or should I create a new index using ES's IndexWriter.
P.S I discovered over the web that this is possible with solr, but afaik couldn't find anything tangible for es. Any help would be appreciated.
You need to reindex into ElasticSearch, you can't reuse an existing Lucene index.
I m using Katta for distributed Lucene Index. Is it possible to use LUKE for Katta index, if so, how? Thanks in advance...
Fair enough. They basically say that a Katta index is a folder containing Lucene indexes.
So what you need to do is:
Install Luke.
Point it at the sub-folders of the Katta index.
See what these indexes' structure is.
I'm looking for some info so that users can find local results in their Lucene.Net searches.
I would index the latitude/longitude of the location in the document, and query Lucene based on the users position and 20 (or 30, 40...) mile range.
The utmost on local search in Lucene is Grant Ingersoll's Location-aware search with Apache Lucene and Solr. Trouble is that Lucene.net lags after Java Lucene, so that these Lucene features available with the rather new Lucene 2.9.0 will take a while to trickle into Lucene.net (Lucene.net 2.4.0 came about a year after Java Lucene's 2.4.0). In the meantime,
try Spatial.net in Lucene.net's contrib, or you can try to port Sujit Pal's suggestions from Java to C#.