Elasticsearch function_score无法正常工作？

Question

I'm using the following function score for outfits purchased:

{
"query": {
    "function_score": {
        "field_value_factor": {
            "field": "purchased",
            "factor": 1.2,
            "modifier": "sqrt",
            "missing": 1
        }
    }
}

}

However, when I create a search - I get the following error:

"type":"illegal_argument_exception","reason":"Fielddata is disabled on text fields by default. Set fielddata=true on [purchased] in order to load fielddata in memory by uninverting the inverted index. Note that this can however use significant memory. Alternatively use a keyword field instead."

The syntax is correct for the search as I've run it locally and it works perfectly. I'm now running it on my server and it's not workings. Do I need to define purchased as an integer somewhere or is this due to something else?

Answer 1

The purchased field is an analyzed string field, hence the error you see.

When indexing your documents, make sure that the numbers are not within double quotes, ie

Wrong:
{
    "purchased": "324"
}

Right:
{
    "purchased": 324
}

...or if you can't change the source documents (because you're not responsible for producing them), make sure that you create a mapping that defines the purchased field as being an integer field.

{
    "your_type": {
        "properties": {
            "purchased": {
                "type": "integer"
            }
        }
    }
}