Sorting

Sorting criteria for the Search hits.

On Search, the Hits are gettings a _score value that indicates how good the Document matches the given query.

The Document with the highest score comes first, and so on.

You can change this behavior on Search-level in the Sigmie UI.

Attributes

You can specify the attributes that are taken into consideration when sorting the Search hits in the Sigmie UI.

Let's say you have an index that contains documents in the following structure.

{
  "name": "Toy Story",
  "category": ["Comedy", "Family"],
  "release_year": "1995",
  "duration_minutes": 81
}

You may want to first show the newest Documents. In this case, you can choose the release_year as a sorting attribute with the direction Desc.

Your Search Hits will be sorted by release_year Ascending. So the newest releases will be shown on top, ignoring the _score attribute.

_score

The _score attribute is a float assigned to Documents indicating how good each Document matches the query, and it's a part of the Hits object.

{
  // ...
  "hits": {
    "AHs3l4IBrbFU6hq5SDCR": {
      // ...
      "_score": 1.3862942
    }
  }
}

How is _score calculated

There are several factors that define the score rating.

1. Term frequency

   The more times a term appears in a Document, the higher its score will be.

2. Inverse document frequency

   If many Documents in the index contain the term, then the term is actually less important.

3. Coordination

   The more query terms in the Document, the higher it will be scored.

4. Field length

   A term found in a short field like name is more important than a term in a longer field like the description field.

5. Field boost

   A term found in a boosted attribute. See Tunning for more.

Direction

Like everywhere, you can choose the sorting direction for your Hits.

Asc

The Asc direction shorts the Hits in Ascending order. So if the sorting attribute is a number, then the Documents with the lowest will come first.

Desc

The Desc direction shorts the Hits in Descending order. So if the sorting attribute is a number, then the Documents with the highest number will be on top.