multivalue or array indexing in elasticsearch

Question

I'd like to know a bit more about the next situation. I'm trying to index a document like this:

PUT 'server/index/test/1'
{
    to: "to1",
    to: "to2",
    to: "to3"
}

Seemingly, elasticsearch swallows this document. Ok , no problem. Nevertheless, I would like to know which are the differences between an array of values.

How the searches are made?

EDITED:

I've tried this searches:

GET 'server/index/test/_search?q=to:to1&pretty'
GET 'server/index/test/_search?q=to:to2&pretty'
GET 'server/index/test/_search?q=to:to3&pretty'

and ES shows me the document after each execution:

{
   "took" : 44,
   "timed_out" : false,
   "_shards" : {
       "total" : 5,
       "successful" : 5,
       "failed" : 0
   },
   "hits" : {
   "total" : 1,
   "max_score" : 1.0,
       "hits" : [ {
           "_index" : "index",
           "_type" : "test",
           "_id" : "1",
           "_score" : 1.0,
           "_source":
           {
               to: "to1",
               to: "to2",
               to: "to3"
           }
       } ]
    }
}

Seemingly, ES indexes every repeated field value also... Is it really like this? Or I'm performing or doing something wrong?

You're indexing the document into the server index, but the response somehow shows that the document is in the living index. Weird, not sure how that's possible. — Val
– Val, Commented Oct 13, 2015 at 8:00
It's just a typing mistake. I've just edited it. server means the url to ES server, that's not the index. The index is index, and the collection is test — Jordi
– Jordi, Commented Oct 13, 2015 at 8:53
Ok, makes sense. What still doesn't make sense, though, is your source with to fields which are not even double-quoted strings. Which tool/plugin are you using to send your queries? — Val
– Val, Commented Oct 13, 2015 at 8:59
Interesting case. Using Sense, I get a Bad string (next to the first to field) warning when retrieving the search results... — Val
– Val, Commented Oct 13, 2015 at 9:32

Val · Accepted Answer · 2015-10-13 06:53:30Z

1

In a JSON document you cannot have two fields with the same name, but ES will silently "fix" your document and only index a single to field. Moreover, since a JSON document is basically a map, which is inherently unordered, you have no guarantee as to which one of the three to fields get indexed.

So if you index that document, it will work, but you'll only see a single to field in it, which is probably not what you want:

PUT 'server/test/1'
{
    to: "to1",
    to: "to2",
    to: "to3"
}

GET 'server/test/1'
{
    to: "to3"            <--- could also be to1 or to2
}

However, if you make to an array of values then all the values will be indexed

PUT 'server/test/1'
{
    to: ["to1", "to2", "to3"]
}

GET 'server/test/1'
{
    to: ["to1", "to2", "to3"]
}

answered Oct 13, 2015 at 6:53

Val

218k14 gold badges377 silver badges384 bronze badges

Sign up to request clarification or add additional context in comments.

1 Comment

Jordi Over a year ago

I've added some searches on my post. It seems ES indexes every repeated field value?

Collectives™ on Stack Overflow

multivalue or array indexing in elasticsearch

1 Answer 1

1 Comment

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

1 Comment

Your Answer

Sign up or log in

Post as a guest

Related