# How to boost nested query under bool should query?

**URL:** <https://discuss.elastic.co/t/how-to-boost-nested-query-under-bool-should-query/94232>\
**Category:** Elasticsearch\
**Created:** [July 23, 2017, 9:44am UTC](https://discuss.elastic.co/t/how-to-boost-nested-query-under-bool-should-query/94232 "2017-07-23T09:44:47Z")\
**Posts on this page:** 7\
**Page:** 1

<div class="post-metadata">

**Author:** ![joonhocho](https://sea2.discourse-cdn.com/elastic/user_avatar/discuss.elastic.co/joonhocho/32/20343_2.png) [@joonhocho](https://discuss.elastic.co/u/joonhocho)\
**Post date:** [July 23, 2017, 9:44am UTC](https://discuss.elastic.co/t/how-to-boost-nested-query-under-bool-should-query/94232/1 "2017-07-23T09:44:47Z")

</div>

I want to boost clauses individually under bool.should query.

Here's my data structure:

```
person = {
  username,
  names: [{first, last}], // nested
  addresses: [{city, state}], // nested
}

```

I want to boost username by 3, names by 2, and addresses by 1.

How can I achieve this?

Omni query text may be something like "john doe san francisco", and I want to boost results with matched names over results with matched addresses.

Here's my query without boost:

```
query: {
  bool: {
    should: [
      {match: {username: text}},
      {
        nested: {
          path: 'names',
          query: {
            multi_match: {
              query: text,
              type: 'cross_fields',
              fields: [
                'names.first',
                'names.last',
              ],
            },
          },
        },
      },
      {
        nested: {
          path: 'addresses',
          query: {
            multi_match: {
              query: text,
              type: 'cross_fields',
              fields: [
                'addresses.city',
                'addresses.state',
              ],
            },
          },
        },
      },
    ],
  },
},
```

---

<div class="post-metadata">

**Author:** ![Mark\_Harwood](https://sea2.discourse-cdn.com/elastic/user_avatar/discuss.elastic.co/mark_harwood/32/10538_2.png) [@Mark\_Harwood](https://discuss.elastic.co/u/Mark_Harwood)\
**Post date:** [July 24, 2017, 9:47am UTC](https://discuss.elastic.co/t/how-to-boost-nested-query-under-bool-should-query/94232/2 "2017-07-24T09:47:12Z")

</div>

> [@joonhocho](#):
>
> I want to boost results with matched names over results with matched addresses.

Careful with blanket statements like this otherwise a man called Francisco may suddenly appear in a lot of results.

Ideally you need to consider on a _per-query_ basis what is the most likely context for each word provided.  
This is what cross\_fields will try do for you because otherwise (as you may have already discovered) default Lucene ranking favours rare terms and therefore the most unlikely context (name.first:Francisco Vs addresses.city:Francisco).  
However, given you have separate clauses for address and person names the cross\_fields logic will not figure out which is the most likely choice between the two contexts.  
If you were to use `copy_to` to root-level person and address index fields you could use a single `cross_fields` multi-match across these fields and it would determine the most appropriate scoring context for each search term. Or alternatively you could just blend all of the terms into a single "all" type field using `copy_to` and use a regular single-field `match` to avoid the oddities of right-word-wrong-context matching that Lucene suffers from.

---

<div class="post-metadata">

**Author:** ![joonhocho](https://sea2.discourse-cdn.com/elastic/user_avatar/discuss.elastic.co/joonhocho/32/20343_2.png) [@joonhocho](https://discuss.elastic.co/u/joonhocho)\
**Post date:** [July 25, 2017, 9:13am UTC](https://discuss.elastic.co/t/how-to-boost-nested-query-under-bool-should-query/94232/3 "2017-07-25T09:13:13Z")

</div>

> [@Mark\_Harwood](#):
>
> Careful with blanket statements like this otherwise a man called Francisco may suddenly appear in a lot of results.

thanks for advice. It makes a lot of sense.

I still wonder if there Is a way to boost any should clause without using cross\_field on root level or copy\_to.  
Because by copying to root level, you lose relationships between properties of a nested objects.

---

<div class="post-metadata">

**Author:** ![Mark\_Harwood](https://sea2.discourse-cdn.com/elastic/user_avatar/discuss.elastic.co/mark_harwood/32/10538_2.png) [@Mark\_Harwood](https://discuss.elastic.co/u/Mark_Harwood)\
**Post date:** [July 25, 2017, 9:22am UTC](https://discuss.elastic.co/t/how-to-boost-nested-query-under-bool-should-query/94232/4 "2017-07-25T09:22:44Z")

</div>

> [@joonhocho](#):
>
> Because by copying to root level, you lose relationships between properties of a nested objects.

It's not always a problem. In policing systems a criminal may use a number of aliases and matching any jumbled combination of previous aliases is a feature not a bug but obviously there are other scenarios where this is not desirable.

---

<div class="post-metadata">

**Author:** ![joonhocho](https://sea2.discourse-cdn.com/elastic/user_avatar/discuss.elastic.co/joonhocho/32/20343_2.png) [@joonhocho](https://discuss.elastic.co/u/joonhocho)\
**Post date:** [July 25, 2017, 9:42am UTC](https://discuss.elastic.co/t/how-to-boost-nested-query-under-bool-should-query/94232/5 "2017-07-25T09:42:33Z")

</div>

Yes it can be a feature, and I agree. However, sometimes your customers or clients may have their own requirements. I guess there is currently no way to boost one should clause with simple boost parameter.

I still think there is a dirty way of mimicking it by copying the same should clause over multiple times to have the same boost effect even though I am afraid it will slow down the search since it's doing the same work multiple times.

---

<div class="post-metadata">

**Author:** ![Mark\_Harwood](https://sea2.discourse-cdn.com/elastic/user_avatar/discuss.elastic.co/mark_harwood/32/10538_2.png) [@Mark\_Harwood](https://discuss.elastic.co/u/Mark_Harwood)\
**Post date:** [July 25, 2017, 9:56am UTC](https://discuss.elastic.co/t/how-to-boost-nested-query-under-bool-should-query/94232/6 "2017-07-25T09:56:31Z")

</div>

The sad truth is users (including myself) are lazy and want to just type words into a single search box and get magic.  
However these are bad queries because there is typically much that is left unstated -

- Does word1 relate to field X or field Y? Francisco the name or the town?
- Do word1 and word2 even relate to the same nested person or are they about different people?

More structured form-based UIs or "did you mean?" type clarifications will help answer the above questions but without this added help from the user it is hard to make a clever solution. Perhaps indexing with shingles will help contextualize input better e.g. the meaning of `diego` changes if you consider a search for the shingle `san diego` Vs `diego maradona`. Surrounding words influence the context.

---

<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:** [August 22, 2017, 9:57am UTC](https://discuss.elastic.co/t/how-to-boost-nested-query-under-bool-should-query/94232/7 "2017-08-22T09:57:36Z")

</div>

This topic was automatically closed 28 days after the last reply. New replies are no longer allowed.