# Nested Documents and Term Facets
**URL:** https://discuss.elastic.co/t/nested-documents-and-term-facets/10103
**Category:** Elasticsearch
**Created:** [December 18, 2012, 2:15am UTC](https://discuss.elastic.co/t/nested-documents-and-term-facets/10103 "2012-12-18T02:15:50Z")
**Posts on this page:** 9
**Page:** 1
### Author:  [@revdev](https://discuss.elastic.co/u/revdev)
#### Post date: [December 18, 2012, 2:15am UTC](https://discuss.elastic.co/t/nested-documents-and-term-facets/10103/1 "2012-12-18T02:15:50Z")
Hi everybody,
I need some help with term\_stats facet when dealing with nested documents.
Assume I have a document mapping like following:
{
"a" : {"type" : "integer" },
"b" : {
"type": "nested",
"include\_in\_root": true,
"c" : { "type" : "integer" },
}
}
I want to know if I can run the following facet:
{
"query": { "match\_all": {} },
"facets": {
"facet1": {
"terms\_stats": {
"key\_field" : "a",
"value\_field": "b.c"
},
"nested": "b"
}
}
}
I am not getting any results using this facet. This could be because since
I have marked it as "nested", its trying to search "a" within the nested
document "b" rather than looking into root object.
Any idea, how I can reference root object "a" when doing a nested facet?
Thanks a lot in advance!
Vinay
--
---
### Author:  [@phill](https://discuss.elastic.co/u/phill)
#### Post date: [December 18, 2012, 5:02am UTC](https://discuss.elastic.co/t/nested-documents-and-term-facets/10103/2 "2012-12-18T05:02:36Z")
I don't believe that is possible when you actually say nested (as
opposed to just an inner object).
Are you saving \_source? I think you might be able to facet on the source.
-Paul
On 12/17/2012 6:15 PM, revdev wrote:
> Hi everybody,
>
> I need some help with term\_stats facet when dealing with nested documents.
> Assume I have a document mapping like following:
>
> ||
> {
> "a":{"type":"integer"},
> "b":{
> "type":"nested",
> "include\_in\_root":true,
> "c":{"type":"integer"},
> }
> }
>
> I want to know if I can run the following facet:
>
> ||
> {
> "query":{"match\_all":{}},
> "facets":{
> "facet1":{
> "terms\_stats":{
> "key\_field":"a",
> "value\_field":"b.c"
> },
> "nested":"b"
> }
> }
> }
>
> I am not getting any results using this facet. This could be because
> since I have marked it as "nested", its trying to search "a" within
> the nested document "b" rather than looking into root object.
> Any idea, how I can reference root object "a" when doing a nested facet?
>
> Thanks a lot in advance!
> Vinay
>
> --
--
---
### Author:  [@revdev](https://discuss.elastic.co/u/revdev)
#### Post date: [December 18, 2012, 5:33am UTC](https://discuss.elastic.co/t/nested-documents-and-term-facets/10103/3 "2012-12-18T05:33:57Z")
Okay. Thanks for clearing that. I am not storing \_source to save space.
I thought storing it in root will allow this type of facet query since it
creates separate documents for nested objects.
On Monday, December 17, 2012 9:02:36 PM UTC-8, P Hill wrote:
> I don't believe that is possible when you actually say nested (as
> opposed to just an inner object).
> Are you saving \_source? I think you might be able to facet on the source.
>
> -Paul
>
> On 12/17/2012 6:15 PM, revdev wrote:
>
> Hi everybody,
>
> I need some help with term\_stats facet when dealing with nested
> documents.
> Assume I have a document mapping like following:
>
> {
> "a" : {"type" : "integer" },
> "b" : {
> "type": "nested",
> "include\_in\_root": true,
> "c" : { "type" : "integer" },
> }
> }
>
> I want to know if I can run the following facet:
>
> {
> "query": { "match\_all": {} },
> "facets": {
> "facet1": {
> "terms\_stats": {
> "key\_field" : "a",
> "value\_field": "b.c"
> },
> "nested": "b"
> }
> }
> }
>
> I am not getting any results using this facet. This could be because
> since I have marked it as "nested", its trying to search "a" within the
> nested document "b" rather than looking into root object.
> Any idea, how I can reference root object "a" when doing a nested facet?
>
> Thanks a lot in advance!
> Vinay
>
> --
--
---
### Author:  [@phill](https://discuss.elastic.co/u/phill)
#### Post date: [December 18, 2012, 7:49pm UTC](https://discuss.elastic.co/t/nested-documents-and-term-facets/10103/4 "2012-12-18T19:49:40Z")
On 12/17/2012 9:33 PM, revdev wrote:
> Okay. Thanks for clearing that. I am not storing \_source to save space.
> I thought storing it in root will allow this type of facet query since
> it creates separate documents for nested objects.
store in root makes it ALSO be stored as an inner object in the root
object, but then you'd need to "store: true" it there in order to get
the value of the field for faceting (or maybe you could use the source,
but does that require a script in the facet?) Then you do your facet on
the root, but be careful, the document in the root will include _all_
the nested objects, not just the matching ones.
This drove me mad for a couple of weeks.
I ended up "inverting" one of my queries, (1) make the nested into
children; (2) use a query on the children that narrows the children and
also any appropriate queries about the parent in the recently added
has\_parent. There is no equivalent to has\_parent for nested objects.
I've learned that has\_children are slower than nested\_queries, due to a
special storage trick for nested documents and their outer documents,
but my queries were fast enough.
Another method I used in another object was to repeat a field or two
from the parent in the child (or nested) so that I didn't need to join
parents with children (or outer with nested).
Buy another Terrabyte drive they cost $100 or less, if you are worried
about storage 🙂
To me this didn't feel right, because I was used to trying for highly
normalized data. But we are not building a DB, we are building an index
to data and some of that data is in the index. Even in DB we repeat data
all the time when we ask for various additional indices. In a database
we just don't see those "denormalized" values resulting from building
various compound and secondary indices out of various fields, but there
really is something out there representing that data again.
-Paul
--
---
### Author:  [@Igor\_Motov](https://discuss.elastic.co/u/Igor_Motov)
#### Post date: [December 18, 2012, 8:12pm UTC](https://discuss.elastic.co/t/nested-documents-and-term-facets/10103/5 "2012-12-18T20:12:45Z")
Yes, with "include\_in\_root" and without "nested", it should
work: [https://groups.google.com/d/topic/elasticsearch/pjoNmosdCPs/discussion · GitHub](https://gist.github.com/4331528)
On Tuesday, December 18, 2012 12:33:57 AM UTC-5, revdev wrote:
> Okay. Thanks for clearing that. I am not storing \_source to save space.
> I thought storing it in root will allow this type of facet query since it
> creates separate documents for nested objects.
>
> On Monday, December 17, 2012 9:02:36 PM UTC-8, P Hill wrote:
>
> > I don't believe that is possible when you actually say nested (as
> > opposed to just an inner object).
> > Are you saving \_source? I think you might be able to facet on the source.
> >
> > -Paul
> >
> > On 12/17/2012 6:15 PM, revdev wrote:
> >
> > Hi everybody,
> >
> > I need some help with term\_stats facet when dealing with nested
> > documents.
> > Assume I have a document mapping like following:
> >
> > {
> > "a" : {"type" : "integer" },
> > "b" : {
> > "type": "nested",
> > "include\_in\_root": true,
> > "c" : { "type" : "integer" },
> > }
> > }
> >
> > I want to know if I can run the following facet:
> >
> > {
> > "query": { "match\_all": {} },
> > "facets": {
> > "facet1": {
> > "terms\_stats": {
> > "key\_field" : "a",
> > "value\_field": "b.c"
> > },
> > "nested": "b"
> > }
> > }
> > }
> >
> > I am not getting any results using this facet. This could be because
> > since I have marked it as "nested", its trying to search "a" within the
> > nested document "b" rather than looking into root object.
> > Any idea, how I can reference root object "a" when doing a nested facet?
> >
> > Thanks a lot in advance!
> > Vinay
> >
> > --
--
---
### Author:  [@revdev](https://discuss.elastic.co/u/revdev)
#### Post date: [December 18, 2012, 9:43pm UTC](https://discuss.elastic.co/t/nested-documents-and-term-facets/10103/6 "2012-12-18T21:43:02Z")
Igor, P Hill, Thanks for the suggestions!
I ended up duplicating the field on which I want to calculate "term\_stats"
and thats working perfectly for now. It's a bit of more storage but that
works since our dataset is not so massive at this point.
Thanks again for detailed answers!
Vinay
On Tuesday, December 18, 2012 12:12:45 PM UTC-8, Igor Motov wrote:
> Yes, with "include\_in\_root" and without "nested", it should work:
> [https://groups.google.com/d/topic/elasticsearch/pjoNmosdCPs/discussion · GitHub](https://gist.github.com/4331528)
>
> On Tuesday, December 18, 2012 12:33:57 AM UTC-5, revdev wrote:
>
> > Okay. Thanks for clearing that. I am not storing \_source to save space.
> > I thought storing it in root will allow this type of facet query since it
> > creates separate documents for nested objects.
> >
> > On Monday, December 17, 2012 9:02:36 PM UTC-8, P Hill wrote:
> >
> > > I don't believe that is possible when you actually say nested (as
> > > opposed to just an inner object).
> > > Are you saving \_source? I think you might be able to facet on the
> > > source.
> > >
> > > -Paul
> > >
> > > On 12/17/2012 6:15 PM, revdev wrote:
> > >
> > > Hi everybody,
> > >
> > > I need some help with term\_stats facet when dealing with nested
> > > documents.
> > > Assume I have a document mapping like following:
> > >
> > > {
> > > "a" : {"type" : "integer" },
> > > "b" : {
> > > "type": "nested",
> > > "include\_in\_root": true,
> > > "c" : { "type" : "integer" },
> > > }
> > > }
> > >
> > > I want to know if I can run the following facet:
> > >
> > > {
> > > "query": { "match\_all": {} },
> > > "facets": {
> > > "facet1": {
> > > "terms\_stats": {
> > > "key\_field" : "a",
> > > "value\_field": "b.c"
> > > },
> > > "nested": "b"
> > > }
> > > }
> > > }
> > >
> > > I am not getting any results using this facet. This could be because
> > > since I have marked it as "nested", its trying to search "a" within the
> > > nested document "b" rather than looking into root object.
> > > Any idea, how I can reference root object "a" when doing a nested facet?
> > >
> > > Thanks a lot in advance!
> > > Vinay
> > >
> > > --
--
---
### Author:  [@Igor\_Motov](https://discuss.elastic.co/u/Igor_Motov)
#### Post date: [December 20, 2012, 3:31pm UTC](https://discuss.elastic.co/t/nested-documents-and-term-facets/10103/7 "2012-12-20T15:31:04Z")
Hi Vinay,
That's what "include\_in\_root" is basically doing, so that you don't have to
duplicate the field yourself.
Igor
On Tuesday, December 18, 2012 4:43:02 PM UTC-5, revdev wrote:
> Igor, P Hill, Thanks for the suggestions!
>
> I ended up duplicating the field on which I want to calculate "term\_stats"
> and thats working perfectly for now. It's a bit of more storage but that
> works since our dataset is not so massive at this point.
> Thanks again for detailed answers!
>
> Vinay
>
> On Tuesday, December 18, 2012 12:12:45 PM UTC-8, Igor Motov wrote:
>
> > Yes, with "include\_in\_root" and without "nested", it should work:
> > [https://groups.google.com/d/topic/elasticsearch/pjoNmosdCPs/discussion · GitHub](https://gist.github.com/4331528)
> >
> > On Tuesday, December 18, 2012 12:33:57 AM UTC-5, revdev wrote:
> >
> > > Okay. Thanks for clearing that. I am not storing \_source to save space.
> > > I thought storing it in root will allow this type of facet query since
> > > it creates separate documents for nested objects.
> > >
> > > On Monday, December 17, 2012 9:02:36 PM UTC-8, P Hill wrote:
> > >
> > > > I don't believe that is possible when you actually say nested (as
> > > > opposed to just an inner object).
> > > > Are you saving \_source? I think you might be able to facet on the
> > > > source.
> > > >
> > > > -Paul
> > > >
> > > > On 12/17/2012 6:15 PM, revdev wrote:
> > > >
> > > > Hi everybody,
> > > >
> > > > I need some help with term\_stats facet when dealing with nested
> > > > documents.
> > > > Assume I have a document mapping like following:
> > > >
> > > > {
> > > > "a" : {"type" : "integer" },
> > > > "b" : {
> > > > "type": "nested",
> > > > "include\_in\_root": true,
> > > > "c" : { "type" : "integer" },
> > > > }
> > > > }
> > > >
> > > > I want to know if I can run the following facet:
> > > >
> > > > {
> > > > "query": { "match\_all": {} },
> > > > "facets": {
> > > > "facet1": {
> > > > "terms\_stats": {
> > > > "key\_field" : "a",
> > > > "value\_field": "b.c"
> > > > },
> > > > "nested": "b"
> > > > }
> > > > }
> > > > }
> > > >
> > > > I am not getting any results using this facet. This could be because
> > > > since I have marked it as "nested", its trying to search "a" within the
> > > > nested document "b" rather than looking into root object.
> > > > Any idea, how I can reference root object "a" when doing a nested facet?
> > > >
> > > > Thanks a lot in advance!
> > > > Vinay
> > > >
> > > > --
--
---
### Author:  [@Vinay\_2](https://discuss.elastic.co/u/Vinay_2)
#### Post date: [December 21, 2012, 12:28am UTC](https://discuss.elastic.co/t/nested-documents-and-term-facets/10103/8 "2012-12-21T00:28:41Z")
The thing is my nested document is not a single object but its an array of
objects which is why I used "nested" property since I want to find only
array objects which match a particular filter.
I tried performing facets by using "include\_in\_root" and omitting "nested"
property in facet query, but then it would return results by collecting
stats from all objects of the array rather than just one or two which match
the facet filter. Hope I was able to explain myself 🙂
On Thu, Dec 20, 2012 at 7:31 AM, Igor Motov [imotov@gmail.com](mailto:imotov@gmail.com) wrote:
> Hi Vinay,
>
> That's what "include\_in\_root" is basically doing, so that you don't have
> to duplicate the field yourself.
>
> Igor
>
> On Tuesday, December 18, 2012 4:43:02 PM UTC-5, revdev wrote:
>
> > Igor, P Hill, Thanks for the suggestions!
> >
> > I ended up duplicating the field on which I want to calculate
> > "term\_stats" and thats working perfectly for now. It's a bit of more
> > storage but that works since our dataset is not so massive at this point.
> > Thanks again for detailed answers!
> >
> > Vinay
> >
> > On Tuesday, December 18, 2012 12:12:45 PM UTC-8, Igor Motov wrote:
> >
> > > Yes, with "include\_in\_root" and without "nested", it should work:
> > > [https://gist.github.com/\*\*4331528](https://gist.github.com/**4331528) [https://gist.github.com/4331528](https://gist.github.com/4331528)
> > >
> > > On Tuesday, December 18, 2012 12:33:57 AM UTC-5, revdev wrote:
> > >
> > > > Okay. Thanks for clearing that. I am not storing \_source to save space.
> > > > I thought storing it in root will allow this type of facet query since
> > > > it creates separate documents for nested objects.
> > > >
> > > > On Monday, December 17, 2012 9:02:36 PM UTC-8, P Hill wrote:
> > > >
> > > > > I don't believe that is possible when you actually say nested (as
> > > > > opposed to just an inner object).
> > > > > Are you saving \_source? I think you might be able to facet on the
> > > > > source.
> > > > >
> > > > > -Paul
> > > > >
> > > > > On 12/17/2012 6:15 PM, revdev wrote:
> > > > >
> > > > > Hi everybody,
> > > > >
> > > > > I need some help with term\_stats facet when dealing with nested
> > > > > documents.
> > > > > Assume I have a document mapping like following:
> > > > >
> > > > > {
> > > > > "a" : {"type" : "integer" },
> > > > > "b" : {
> > > > > "type": "nested",
> > > > > "include\_in\_root": true,
> > > > > "c" : { "type" : "integer" },
> > > > > }
> > > > > }
> > > > >
> > > > > I want to know if I can run the following facet:
> > > > >
> > > > > {
> > > > > "query": { "match\_all": {} },
> > > > > "facets": {
> > > > > "facet1": {
> > > > > "terms\_stats": {
> > > > > "key\_field" : "a",
> > > > > "value\_field": "b.c"
> > > > > },
> > > > > "nested": "b"
> > > > > }
> > > > > }
> > > > > }
> > > > >
> > > > > I am not getting any results using this facet. This could be because
> > > > > since I have marked it as "nested", its trying to search "a" within the
> > > > > nested document "b" rather than looking into root object.
> > > > > Any idea, how I can reference root object "a" when doing a nested
> > > > > facet?
> > > > >
> > > > > Thanks a lot in advance!
> > > > > Vinay
> > > > >
> > > > > --
> > > > >
> > > > > --
--
---
### Author:  [@system](https://discuss.elastic.co/u/system)
#### Post date: [July 6, 2017, 2:58am UTC](https://discuss.elastic.co/t/nested-documents-and-term-facets/10103/9 "2017-07-06T02:58:54Z")