_source vs stored fields

Elastic Stack Elasticsearch
1

Hi,

ElasticSearch supports two ways of storing data. Every field has a store
option and there is a special _source fields which stores the original JSON.

I was wondering what are the rule thumbs to choose the one over the other
(or both?) - performance being the most important factor.

Our application needs to support for two main use cases:

  1. Straight forward searching, where full documents are returned, with hit
    highlighting.
  2. Faceting where we need access to document tokens and metadata fields
    like date.

Thanks for your advice,
Boaz

2

Hi Boaz

Our application needs to support for two main use cases:

  1. Straight forward searching, where full documents are returned, with
    hit highlighting.
  2. Faceting where we need access to document tokens and metadata
    fields like date.

You don't need _stored fields for either of these. Also, take a look
at:
https://groups.google.com/d/topic/elasticsearch/j8cfbv-j73g/discussion

clint

3

Hi Clint,

Thank you for the reply. I was wondering how this relates to the field
cache - does it store the content of the _source field or does store the
tokenized version of regular fields (or maybe I'm completely off thinking
it's related).

Cheers,
Boaz

On Friday, June 8, 2012 11:58:24 PM UTC+2, Clinton Gormley wrote:

Hi Boaz

Our application needs to support for two main use cases:

  1. Straight forward searching, where full documents are returned, with
    hit highlighting.
  2. Faceting where we need access to document tokens and metadata
    fields like date.

You don't need _stored fields for either of these. Also, take a look
at:
https://groups.google.com/d/topic/elasticsearch/j8cfbv-j73g/discussion

clint

4

Hi Boaz

Thank you for the reply. I was wondering how this relates to the field
cache - does it store the content of the _source field or does store
the tokenized version of regular fields (or maybe I'm completely off
thinking it's related).

As I understand it, the field cache stores tokens, so the _source field
or store parameter are irrelevant, as both of these just store the
original value, not the tokenized value.

clint