CODEWITHSUNDEEP
elasticsearch
eran
eran

Reputation: 15156

What indexes are created when indexing a document in elasticsearch

If I create a first document of it's type, or put a mapping, is an index created for each field?

Obviously if i set "index" to "analyzed" or "not analyzed" the field is indexed.

Is there a way to store a field so it can be retrieved but never searched by? I imagine this will save a lot of space? If I set this to "no" will this save space?

Will I still be able to search by this, just take more time, or will this be totally unsearchable?

Is there a way to make a field indexed after some documents are inserted and I change my mind?

For example, I might have a mapping:

{
 "book":{"properties":{
     "title":{"type":"string", "index":"not_analyzed"},
     "shelf":{"type":"long","index":"no"}
}}}

so I want to be able to search by title, but also retrieve the shelf the book is on

Upvotes: 0

Views: 351

Answers (1)

Geert-Jan
Geert-Jan

Reputation: 18925

index:no will indeed not create an index for that field, so that saves some space. Once you've done that you can't search for that particular field anymore.

Perhaps also useful in this context is to know aboutthe _source field, which is returned by default and includes all fields you've stored. http://www.elasticsearch.org/guide/reference/mapping/source-field/

As to your second question: you can't change your mind halfway. When you want to index a particular field later on you have to reindex the documents.

That's why you may want to reconsider setting index:no, etc. In fact a good strategy to begin is to don't define a schema for fields at all, unless you're 100% sure you need a non-default analyzer for a particular field for instance. Otherwise ES will use generally usable defaults.

Upvotes: 1

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