# Behavior of multi\_field at index and query time

**URL:** <https://discuss.elastic.co/t/behavior-of-multi-field-at-index-and-query-time/20939>\
**Category:** Elasticsearch\
**Created:** [November 25, 2014, 3:20pm UTC](https://discuss.elastic.co/t/behavior-of-multi-field-at-index-and-query-time/20939 "2014-11-25T15:20:49Z")\
**Posts on this page:** 3\
**Page:** 1

<div class="post-metadata">

**Author:** ![nilsga](https://sea2.discourse-cdn.com/elastic/user_avatar/discuss.elastic.co/nilsga/32/482_2.png) [@nilsga](https://discuss.elastic.co/u/nilsga)\
**Post date:** [November 25, 2014, 3:20pm UTC](https://discuss.elastic.co/t/behavior-of-multi-field-at-index-and-query-time/20939/1 "2014-11-25T15:20:49Z")

</div>

We have a mapping where one of the fields is an integer, but we want to  
change this to a double. We want to avoid re-indexing, since there will be  
a lot of documents at migration time. Hence, we were considering using a  
"multi\_field" (now apparently deprecated, but I guess the same applies for  
the "fields" of a property) for this scenario, where the field is both  
treated as an integer and a double. This means that on the day of  
migration, all the old documents will only have the integer value set, and  
all new documents will have the double value set. In our code, we will only  
treat this value as a double. We have been doing some testing, and it seems  
like it should work, but I would like to confirm our findings as expected  
rather than "by chance". Let's call the field "the\_field", and the double  
property "double", like this:

"the\_field": {  
"type": "integer",  
"fields": {  
"double": {  
"type": "double"  
}  
}  
}

- Without changing our indexing code, when writing a double value to  
"the\_field", the value is automatically written to the field as a double.  
When fetching the document back, the value of "the\_field" is a double. New  
and old documents looks the same. Old documents have integer values and new  
documents have the double values for "the\_field". I would expect new  
documents to have "the\_field.double" in the result instead, but this does  
not seem to be the case (which is good for us, if that is intended).
- When querying "the\_field", say with a range query, both old and new  
documents appear in the result, but the double part of the value in the new  
documents are ignored. So 2.534 is treated as the value 2 in the range (or  
in sorting). This means that if the range is "lte: 2", then even double  
values up to \< 3 are included in the range.
- When querying "the\_field.double", say with a range query both old and new  
documents appear in the result, and the values from both old and new  
documents are treated as double values, as opposed to the previous example.  
So if the range is "lte: 2", then only integer _and_ double values \< 2 are  
included in the range.

Are these observations correct, and as expected? Or is it a "side effect"  
of some kind that we should not rely upon? And I assume the rules for  
queries also applies to aggregations? If this is in fact expected behavior,  
is it possible to "alias" "the\_field.double" to "the\_field" in queries, so  
it is by default treated as the double value?

Regards,

Nils-Helge Garli Hegvik

--  
You received this message because you are subscribed to the Google Groups "elasticsearch" group.  
To unsubscribe from this group and stop receiving emails from it, send an email to [elasticsearch+unsubscribe@googlegroups.com](mailto:elasticsearch+unsubscribe@googlegroups.com).  
To view this discussion on the web visit [https://groups.google.com/d/msgid/elasticsearch/7bcc14c6-3849-4d42-bbe4-3467e52bda52%40googlegroups.com](https://groups.google.com/d/msgid/elasticsearch/7bcc14c6-3849-4d42-bbe4-3467e52bda52%40googlegroups.com).  
For more options, visit [https://groups.google.com/d/optout](https://groups.google.com/d/optout).

---

<div class="post-metadata">

**Author:** ![nilsga](https://sea2.discourse-cdn.com/elastic/user_avatar/discuss.elastic.co/nilsga/32/482_2.png) [@nilsga](https://discuss.elastic.co/u/nilsga)\
**Post date:** [November 27, 2014, 1:50pm UTC](https://discuss.elastic.co/t/behavior-of-multi-field-at-index-and-query-time/20939/2 "2014-11-27T13:50:20Z")

</div>

I hate to bump this post, but I would really appreciate if anyone has any  
input regarding this.

Regards,

Nils-Helge Garli Hegvik

On Tuesday, November 25, 2014 4:20:49 PM UTC+1, [nil...@gmail.com](mailto:nil...@gmail.com) wrote:

> We have a mapping where one of the fields is an integer, but we want to  
> change this to a double. We want to avoid re-indexing, since there will be  
> a lot of documents at migration time. Hence, we were considering using a  
> "multi\_field" (now apparently deprecated, but I guess the same applies for  
> the "fields" of a property) for this scenario, where the field is both  
> treated as an integer and a double. This means that on the day of  
> migration, all the old documents will only have the integer value set, and  
> all new documents will have the double value set. In our code, we will only  
> treat this value as a double. We have been doing some testing, and it seems  
> like it should work, but I would like to confirm our findings as expected  
> rather than "by chance". Let's call the field "the\_field", and the double  
> property "double", like this:
> 
> "the\_field": {  
> "type": "integer",  
> "fields": {  
> "double": {  
> "type": "double"  
> }  
> }  
> }
> 
> - Without changing our indexing code, when writing a double value to  
> "the\_field", the value is automatically written to the field as a double.  
> When fetching the document back, the value of "the\_field" is a double. New  
> and old documents looks the same. Old documents have integer values and new  
> documents have the double values for "the\_field". I would expect new  
> documents to have "the\_field.double" in the result instead, but this does  
> not seem to be the case (which is good for us, if that is intended).
> - When querying "the\_field", say with a range query, both old and new  
> documents appear in the result, but the double part of the value in the new  
> documents are ignored. So 2.534 is treated as the value 2 in the range (or  
> in sorting). This means that if the range is "lte: 2", then even double  
> values up to \< 3 are included in the range.
> - When querying "the\_field.double", say with a range query both old and  
> new documents appear in the result, and the values from both old and new  
> documents are treated as double values, as opposed to the previous example.  
> So if the range is "lte: 2", then only integer _and_ double values \< 2 are  
> included in the range.
> 
> Are these observations correct, and as expected? Or is it a "side effect"  
> of some kind that we should not rely upon? And I assume the rules for  
> queries also applies to aggregations? If this is in fact expected behavior,  
> is it possible to "alias" "the\_field.double" to "the\_field" in queries, so  
> it is by default treated as the double value?
> 
> Regards,
> 
> Nils-Helge Garli Hegvik

--  
You received this message because you are subscribed to the Google Groups "elasticsearch" group.  
To unsubscribe from this group and stop receiving emails from it, send an email to [elasticsearch+unsubscribe@googlegroups.com](mailto:elasticsearch+unsubscribe@googlegroups.com).  
To view this discussion on the web visit [https://groups.google.com/d/msgid/elasticsearch/52160e2d-0c9b-4f81-8a1d-e0e2b9afd437%40googlegroups.com](https://groups.google.com/d/msgid/elasticsearch/52160e2d-0c9b-4f81-8a1d-e0e2b9afd437%40googlegroups.com).  
For more options, visit [https://groups.google.com/d/optout](https://groups.google.com/d/optout).

---

<div class="post-metadata">

**Author:** ![system](https://us1.discourse-cdn.com/elastic/original/3X/1/a/1ac57faf039f6b580b3f104ef42a2a89e41014de.png) [@system](https://discuss.elastic.co/u/system)\
**Post date:** [July 6, 2017, 12:47am UTC](https://discuss.elastic.co/t/behavior-of-multi-field-at-index-and-query-time/20939/3 "2017-07-06T00:47:16Z")

</div>

Closed on July 6, 2017, 12:47am UTC