Elasticsearch Collapsing Based on Text Similarity

Question

I'm working with Elasticsearch and trying to come up with a way to filter a text field based on a phrase. I have basic searching working, but I also want to collapse "similar" results rather than duplicating them.

For example, given 5 objects with text content as

Buy 1 car get one car free until March
Buy 1 car get one car free until April
50% off your car insurance when you buy through us
Get 50% off your oven

If searching for car then I'd be looking for 2 results:

50% off your car insurance [...]
EITHER of the 1st or 2nd one (with both showing in inner_hits)

I've tried to do this using collapse on the content field but that will only collapse on exact matches.

    'query' => [
        'match' => [
            'content' => 'car',
        ],
    ],
    'collapse' => [
        'field' => 'content',
        'inner_hits' => [
            'name' => 'recently_seen_on',
            'size' => 3,
            'sort' => [['seen_on' => 'desc']],
         ],
     ],

I've also tried creating adding a similarity property to the content field but I couldn't figure out if it's possible to collapse using that.

I also come across this https://www.elastic.co/guide/en/elasticsearch/reference/master/search-aggregations-bucket-significanttext-aggregation.html but when I tried something similar I got 0 result. I set the content type to keywords in the mappings:

[
    'content' => ['type' => 'keyword'],
]

And then using:

'query' => [
    'match' => [
        'content' => 'car',
    ],
],
'aggs' => [
    'keywords' => [
        'significant_text' => [
            'field' => 'content',
            'filter_duplicate_text' => true,
        ],
    ],
],

Is achieving something like this possible without coming adding a field that groups fields based on content manually?

Elasticsearch Collapsing Based on Text Similarity

0 Answers