What is elasticsearch?It’s a great question,different people describe this in different ways.A recent video where people are confused to describe elasticsearch What is elasticsearch?.As i know in single word,elasticsearch is a open source search engine.But more often it’s readily-scalable,distributed,full text search engine with RESTful HTTP interface and powerful fast searches data,works on schema free json document which is developed by JAVA based on Apache Lucene.Take breath now!!
Shay Banon created the precursor to Elasticsearch.
Conventional SQL are not really designed for full text search.Where conventional query take more than 10 seconds to get data,in here elasticsearch take under 10 milliseconds to get data.Instead of search text directly,elasticsearch searches an index.During an indexing operation,elasticsearch converts raw data or any message into internal document and store them in JSON object.
ElasticSearch uses Apache Lucene to create and manage inverted index,which is allow very fast full text search.An inverted index consist a list of all unique words which can found in any documents,and for each word a list of document.
It’s important that elasticsearch isn’t a realational database,so RDBMS or DBMS system are vanished,it’s schema free.Elasticsearch hasn’t normalization,join,subquery.
Elasticsearch can handle huge amount of data volume and distribute it in multiple machine and scalable with fault-tolerant.