String sorting in Elasticsearch
We should not sort on analyzed text field instead we should sort on not_analyzed text field. Let's understand this with an example: Index some documents with a text field "name"....
Elasticsearch plugin for Sentiment Analysis
I have created an Elasticsearch plugin for sentiment-analysis using Stanford CoreNLP libraries. The plugin is compatible with Elasticsearch 6.4.1. Follow the below steps to use this plugin with your elasticsearch...
What is Type Safety ?
Definition Type safety is prevention of typed errors in a programming language. A type error occurs when someone attempts to perform an operation on a value that doesn’t support that operation. In simple...
Example of Java 8 Streams groupingBy feature
Statement: Let's say you have a list of integers which you want to group into even and odd numbers. Create a list of integers with four values 1,2,3 and 4: List<Integer>...
Usage of Index Alias in Elasticsearch
An index alias is another name for an index or group of indices. It can substitute the original index name in any API. Using index alias you can: Create “views” on a...
Elasticsearch 6.x Analyzers
Elasticsearch Analyzer is a wrapper which wraps three functions: Character filter: Mainly used to strip off some unused characters or change some characters. Tokenizer: Breaks a text into individual tokens(or words) based on...
Why ES 6.x doesn’t allow multiple types?
Before Elasticsearch6.x, the analogy wrt Relational Databases was: Relational DB ⇒ Databases ⇒ Tables ⇒ Rows ⇒ Columns Elasticsearch ⇒ Indices ⇒ Types ⇒ Documents ⇒ Fields which led to...
How to re-index an index in Elasticsearch using Java ?
To re-index an index using java, build a re-index request using ReindexRequestBuilder API like: ReindexRequestBuilder reindexRequest = new ReindexRequestBuilder(client,ReindexAction.INSTANCE) .source("source_index") .destination("destination_index") .refresh(true); After creating a request execute the request: reindexRequest.execute();...
Reflections in java
Reflection is a powerful feature of Java which provides the ability to inspect & modify the code at run time (manipulate internal properties of the program). For example: It's possible for...
Stop the world phase
Garbage Collection literally stops the world. When a GC occurs in young generation space, it is completed quickly as the young generation space is small. Young generation space is the space...