Indexing tree-like structures

Trees! Trees are everywhere. If you develop a shop application, you probably have categories. If you look at the filesystem, the files and directories are arranged in tree-like structures. This book may also be represented as a tree; chapters contain topics and subtopics. ElasticSearch has functionalities that help us handle tree-like structures. Let's check how we can navigate such data using path_analyzer.

First we'll create a simple mapping:

{
 "settings" : {
  "index" : {
   "analysis" : {
    "analyzer" : {
     "path_analyzer" : {"tokenizer" : "path_hierarchy"}
    }
   }
  }
 },
 "mappings" : {
  "category" : {
   "properties" : {
    "category" : { 
     "type" : "multi_field",
     "fields" : {
      "name" : { "type" : "string", "index" : "not_analyzed" },
      "path" : { "type" : "string", "analyzer" : "path_analyzer", "store" : true }
     }
    }
   }
  }
 }
} 

In order to put those mappings during index creation use the following command:

curl -XPOST...