DevOps Classroomnotes 24/Feb/2022

Mappings and datatypes

  • ElasticSearch is schema less, i.e. we can store documents with any number of fields and types of fields.
  • There are always some set of fields common across all documents in a type.
  • Core Data Types
    • String Data types
      • text: The text datatype is useful for supporting full-text search for fields that contain a description or lenghty text values. Thes fields are analyzed before indexing to support full-text search
      • keyword: This type enable analytics on string fields. Fields of this type support sorting, filtering and aggregations
    • Numeric data types:
      • byte, short, integer and long
      • float and double
      • half_float
      • scaled_float
    • Date datatype:
      • data: Date with an optional timestamp
    • Boolean datatype:
      • boolean:
    • Binary datatype:
      • binary: Allows us to store binary with Base64 encoding
    • Range datatypes:
      • integer_range, float_range, long_range, double_range, data_range
  • Complex Data types:
    • Array datatype:
    • Object data types:
    • Nested data type:
  • Other datatypes:
    • Geo-point datatype
    • Geo-shape datatype
    • IP datatype

Understanding Mapping

  • In the last session we have inserted a data to the index qualitythought

Inverted Indexes

  • Consider we have the following documents with text inserted into elastic search
Document ID Document
1 Its Friday tomorrow
2 Friday night is beginining of Weekend
3 The best day of the week is your choice
4 This week is best for sales
  • Elastic search builds a data structure from the three documents that have been indexed. This data structure is called as inverted index
  • Documents will be broken down into terms after removing puncutation and placing them in LowerCase
  • Terms are sorted alphabetically
  • When searching for terms in the documents, it is blazingly fast to locate the document in which given terms appear.

CRUD Operations

  • To understand how to perform CRUD Operations, we will look into following APIs under document API
  • Index API
  • Get API
  • Update API
  • Delete API

Index API

  • Adding a document to a type within an index of elastic search is called as indexing.
  • There are two ways to index a document
  • Indexing a document by providing an ID
  • Indexing a document by without providing an ID


  • This API is used to retrieve documents

Update API

  • This is used to update a document.

Delete API


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