# Confirm that I don't need \`type: nested\` on every node of my index mapping for the document tree? **URL:** \ **Category:** Elasticsearch\ **Created:** [February 7, 2023, 1:36pm UTC](https://discuss.elastic.co/t/confirm-that-i-dont-need-type-nested-on-every-node-of-my-index-mapping-for-the-document-tree/324907 "2023-02-07T13:36:54Z")\ **Posts on this page:** 9\ **Page:** 1
**Author:** ![learningelastic](https://avatars.discourse-cdn.com/v4/letter/l/958977/32.png) [@learningelastic](https://discuss.elastic.co/u/learningelastic)\ **Post date:** [February 7, 2023, 1:36pm UTC](https://discuss.elastic.co/t/confirm-that-i-dont-need-type-nested-on-every-node-of-my-index-mapping-for-the-document-tree/324907/1 "2023-02-07T13:36:54Z")
I just have a question about the `type: nested` in the index mappings. Let's say I have documents where I want to aggregate on `order.order_items.product.manufacturer.contact.name`. Initially I made my mapping like this ```auto { "properties": { "order_items": { "type": "nested", "properties": { "quantity": { "type": "long" }, "product": { "type": "nested", "properties": { "name": { "type": "keyword" }, "manufacturer": { "type": "nested", "properties": { "name": "{ "type": "keyword" }, "contact": { "type": "nested", "properties": { "name": {"type": "keyword"} } } } } } } } } ...other fields... } } ``` That is, I placed `"type": "nested"` on every node of the document tree. But through experimentation it seems like this was unnecessary. Seems like I only needed to put `"type":"nested"` only on the `contact` nested object. And if I only wanted to aggregate on `order.order_items.product.name`, then I only need to apply `"type":"nested"` on the `product` nested object. I just wanted to confirm my findings with someone who knows this stuff just to make sure I didn't misunderstand anything, or if there's other interesting insights I should be aware about. ---
**Author:** ![Christian\_Dahlqvist](https://sea2.discourse-cdn.com/elastic/user_avatar/discuss.elastic.co/christian_dahlqvist/32/4617_2.png) [@Christian\_Dahlqvist](https://discuss.elastic.co/u/Christian_Dahlqvist)\ **Post date:** [February 7, 2023, 1:52pm UTC](https://discuss.elastic.co/t/confirm-that-i-dont-need-type-nested-on-every-node-of-my-index-mapping-for-the-document-tree/324907/2 "2023-02-07T13:52:24Z")
What does a sample document look like? ---
**Author:** ![learningelastic](https://avatars.discourse-cdn.com/v4/letter/l/958977/32.png) [@learningelastic](https://discuss.elastic.co/u/learningelastic)\ **Post date:** [February 7, 2023, 2:08pm UTC](https://discuss.elastic.co/t/confirm-that-i-dont-need-type-nested-on-every-node-of-my-index-mapping-for-the-document-tree/324907/3 "2023-02-07T14:08:12Z")
If I do a `GET order/_search`, one of the hits could be : ```auto { "order_items": [ { "product": { "name": "smart phone", "manufacturer": { "name": "Acme Limited", "phone": "111-111-1111", "contact": { "name": "George", "phone": "555-555-5555" } } "quantity": 1200 } } ], "customer": { "zip": 36571, "geo": { "zip": 36571, "point": "POINT(-87.52 34.46)" }, "address": "1095 Industrial Pkwy", "city": "Saraland", "state": "AL", "customer_id": 219, "birth_year": 1967 } } ``` ---
**Author:** ![Christian\_Dahlqvist](https://sea2.discourse-cdn.com/elastic/user_avatar/discuss.elastic.co/christian_dahlqvist/32/4617_2.png) [@Christian\_Dahlqvist](https://discuss.elastic.co/u/Christian_Dahlqvist)\ **Post date:** [February 7, 2023, 2:40pm UTC](https://discuss.elastic.co/t/confirm-that-i-dont-need-type-nested-on-every-node-of-my-index-mapping-for-the-document-tree/324907/4 "2023-02-07T14:40:10Z")
As far as I can tell, the only field that need to be nested is likely `order_items` as this has an array of subdocuments and you may want to filter on multiple fileds within order items. ---
**Author:** ![learningelastic](https://avatars.discourse-cdn.com/v4/letter/l/958977/32.png) [@learningelastic](https://discuss.elastic.co/u/learningelastic)\ **Post date:** [February 7, 2023, 3:16pm UTC](https://discuss.elastic.co/t/confirm-that-i-dont-need-type-nested-on-every-node-of-my-index-mapping-for-the-document-tree/324907/5 "2023-02-07T15:16:50Z")
Thanks! I actually did an experiment where I placed `type: nested` only on the `order_items`. But the `type: nested` didn't seem to have down stream effect on children that are also nested. It seemed in my experiments that `type: nested` has to be applied to the specific child you wish to aggregate on. So that's why just wanted to confirm with you and others if I misunderstood something ---
**Author:** ![Christian\_Dahlqvist](https://sea2.discourse-cdn.com/elastic/user_avatar/discuss.elastic.co/christian_dahlqvist/32/4617_2.png) [@Christian\_Dahlqvist](https://discuss.elastic.co/u/Christian_Dahlqvist)\ **Post date:** [February 7, 2023, 4:23pm UTC](https://discuss.elastic.co/t/confirm-that-i-dont-need-type-nested-on-every-node-of-my-index-mapping-for-the-document-tree/324907/6 "2023-02-07T16:23:08Z")
> [@learningelastic](#): > > But the `type: nested` didn't seem to have down stream effect on children that are also nested. What does this mean? It would help if you provided the full mapping as well as the query for this scenario. ---
**Author:** ![learningelastic](https://avatars.discourse-cdn.com/v4/letter/l/958977/32.png) [@learningelastic](https://discuss.elastic.co/u/learningelastic)\ **Post date:** [February 7, 2023, 9:20pm UTC](https://discuss.elastic.co/t/confirm-that-i-dont-need-type-nested-on-every-node-of-my-index-mapping-for-the-document-tree/324907/7 "2023-02-07T21:20:22Z")
Ok I simplified my question to this. My goal is to eventually aggregate on the field `order.order_items.produce.name`. This SCENARIO 1 works completely fine: **SCENARIO 1** ```auto DELETE order PUT order POST order/_mapping { "properties": { "order_items": { "properties": { "product_id": { "type": "long" }, "product": { "type": "nested", "properties": { "name": { "type": "keyword" }, "product_id": { "type": "long" }, "price": { "type": "long" } } } } } } } POST order/_bulk {"index":{}} {"order_items":[{"product":{"name":"book","price":10}},{"product":{"name":"pencil","price":1}}]} {"index":{}} {"order_items":[{"product":{"name":"pen","price":5}},{"product":{"name":"eraser","price":1}}]} GET order/_search { "size": 0, "aggs": { "order": { "nested": { "path": "order_items.product" }, "aggs": { "product_name" : { "terms": { "field": "order_items.product.name" }, "aggs": { "avg_price": { "avg": { "field": "order_items.product.price" } } } } } } } } ``` The final `GET order/_search {...}` shows results like this ```auto { ...other fields... "aggregations": { "order": { "doc_count": 4, "product_name": { "doc_count_error_upper_bound": 0, "sum_other_doc_count": 0, "buckets": [ { "key": "book", "doc_count": 1, "avg_price": { "value": 10 } }, { "key": "eraser", "doc_count": 1, "avg_price": { "value": 1 } }, { "key": "pen", "doc_count": 1, "avg_price": { "value": 5 } }, { "key": "pencil", "doc_count": 1, "avg_price": { "value": 1 } } ] } } } ``` Now SCENARIO 2 below doesn't yield and results: **SCENARIO 2:** ```auto DELETE order PUT order POST order/_mapping { "properties": { "order_items": { "type": "nested", "properties": { "product_id": { "type": "long" }, "product": { "properties": { "name": { "type": "keyword" }, "product_id": { "type": "long" }, "price": { "type": "long" } } } } } } } POST order/_bulk {"index":{}} {"order_items":[{"product":{"name":"book","price":10}},{"product":{"name":"pencil","price":1}}]} {"index":{}} {"order_items":[{"product":{"name":"pen","price":5}},{"product":{"name":"eraser","price":1}}]} GET order/_search { "size": 0, "aggs": { "order": { "nested": { "path": "order_items.product" }, "aggs": { "product_name" : { "terms": { "field": "order_items.product.name" }, "aggs": { "avg_price": { "avg": { "field": "order_items.product.price" } } } } } } } } ``` The final `GET order/_search {...}` shows zero results like this ```auto { ... other fields ... "aggregations": { "order": { "doc_count": 0, "product_name": { "doc_count_error_upper_bound": 0, "sum_other_doc_count": 0, "buckets": [] } } } } ``` The difference between Scenario 1 and Scenario 2 is simply the placement of the `type: nested` attribute in the mapping. Placing `type: nested` at the `order_items` level does not have any down stream effect to the `product` level. That's why in Scenario 2, placing `type: nested` at the `order_items` level does nothing for the `GET order/_search` in terms of aggregation, which yields zero results. ---
**Author:** ![learningelastic](https://avatars.discourse-cdn.com/v4/letter/l/958977/32.png) [@learningelastic](https://discuss.elastic.co/u/learningelastic)\ **Post date:** [February 7, 2023, 9:53pm UTC](https://discuss.elastic.co/t/confirm-that-i-dont-need-type-nested-on-every-node-of-my-index-mapping-for-the-document-tree/324907/8 "2023-02-07T21:53:28Z")
OH wait, I can also get results in the search query for scenario 2 if I change the nested path from `aggs.order.nested.path: order_items.product` to `aggs.order.nested.path: order_items` ```auto GET order/_search { "size": 0, "aggs": { "order": { "nested": { "path": "order_items.product" }, "aggs": { "product_name" : { "terms": { "field": "order_items.product.name" }, "aggs": { "avg_price": { "avg": { "field": "order_items.product.price" } } } } } } } } ``` Ok, so it doesn't matter where you place the `type: nested` in the mapping as long as your specify a corresponding `nested.path` in the search query? I'll open a second question about this... ---
**Author:** ![system](https://us1.discourse-cdn.com/elastic/original/3X/1/a/1ac57faf039f6b580b3f104ef42a2a89e41014de.png) [@system](https://discuss.elastic.co/u/system)\ **Post date:** [March 7, 2023, 9:53pm UTC](https://discuss.elastic.co/t/confirm-that-i-dont-need-type-nested-on-every-node-of-my-index-mapping-for-the-document-tree/324907/9 "2023-03-07T21:53:40Z")
This topic was automatically closed 28 days after the last reply. New replies are no longer allowed.