Elasticsearch: The Definitive Guide Learning Chapter 10 Index Management

Creating an Index

Deleting an Index

Configuring Analyzers

Types and Mappings

A type consists of a name-- such as user or blogpost – and a mapping. The mapping, like a database schema, describes the fields or properties that documents of that type may have, the datatype of each field-- such as string, integer, or date — and how those fields should be indexed and stored by Lucence.

How Lucence Sees Documents

A document in Lucene consists of a simple list of field-value pairs. A field must have at least one value, but any field can contain multiple values. When we index a document in Lucene, the values for each field are added to the inverted index for the associated field. Optionally, the original values may also be stored unchanged so that they can be retrieved later.

How types are implemented

The type name of each document is stored with the document in a metadata field called _type. WHen we search for documents of a particular type, Elasticsearch simply uses a filter on the _type field to restrict results to documents of that type.

Dynamic Mapping

dynamic_templates

Default Mapping

Reindexing Your Data

The simplest way to apply these changes to your existing dta is to reindex: create a new index with the new settings and copy all of your documents from the old index to the new index.

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