Does early termination (sorted index) kick in in this case?

[jmlucjav]

I have such an index (ES 7.4):

    "index": {
        "sort.field": "date",
        "sort.order": "desc",

And I query like this:

    {
    "sort": [
        "_score",
        {
            "date": {
                "order": "desc"
            }
        }
    ],
    "track_total_hits": false,
    "query": {
                    "multi_match": {
                        "query": "banana",
                        "fields": [
                            "title^2"                     
                        ]
                    }
        }
    }
    }

And important detail, title field is like this:

            "title": {
                "type": "text",
                "analyzer": "custom_text",
                "search_analyzer": "custom_search",
                "similarity": "boolean"
            },

so its using boolean similarity. As such max score for docs will be 2 (boost value). Even if we sort by score first, by date later, as the max score is known, early termination could be used here. But I cannot assert by looking at my experiments, as I have only a very small index to test.

So, is it being used?

thanks

[spinscale (Alexander Reelsen)]

If you sort by score, then index sorting will not apply.

What could however still apply is the block max-WAND. See https://www.elastic.co/blog/faster-retrieval-of-top-hits-in-elasticsearch-with-block-max-wand

[jmlucjav]

ok, makes sense...

Yeah, max-WAND would apply but this would happen even if the index was date-sorted.

thanks!