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Text field type

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Text field type

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A field to index full-text values, such as the body of an email or the description of a product. These fields are analyzed, that is they are passed through an analyzer to convert the string into a list of individual terms before being indexed. The analysis process allows Elasticsearch to search for individual words within each full text field. Text fields are not used for sorting and seldom used for aggregations (although the significant text aggregation is a notable exception).

If you need to index structured content such as email addresses, hostnames, status codes, or tags, it is likely that you should rather use a keyword field.

Below is an example of a mapping for a text field:

PUT my-index-000001
{
  "mappings": {
    "properties": {
      "full_name": {
        "type":  "text"
      }
    }
  }
}

Use a field as both text and keyword

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Sometimes it is useful to have both a full text (text) and a keyword (keyword) version of the same field: one for full text search and the other for aggregations and sorting. This can be achieved with multi-fields.

Parameters for text fields

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The following parameters are accepted by text fields:

`analyzer`	The analyzer which should be used for the `text` field, both at index-time and at search-time (unless overridden by the `search_analyzer`). Defaults to the default index analyzer, or the `standard` analyzer.
`boost`	Mapping field-level query time boosting. Accepts a floating point number, defaults to `1.0`.
`eager_global_ordinals`	Should global ordinals be loaded eagerly on refresh? Accepts `true` or `false` (default). Enabling this is a good idea on fields that are frequently used for (significant) terms aggregations.
`fielddata`	Can the field use in-memory fielddata for sorting, aggregations, or scripting? Accepts `true` or `false` (default).
`fielddata_frequency_filter`	Expert settings which allow to decide which values to load in memory when `fielddata` is enabled. By default all values are loaded.
`fields`	Multi-fields allow the same string value to be indexed in multiple ways for different purposes, such as one field for search and a multi-field for sorting and aggregations, or the same string value analyzed by different analyzers.
`index`	Should the field be searchable? Accepts `true` (default) or `false`.
`index_options`	What information should be stored in the index, for search and highlighting purposes. Defaults to `positions`.
`index_prefixes`	If enabled, term prefixes of between 2 and 5 characters are indexed into a separate field. This allows prefix searches to run more efficiently, at the expense of a larger index.
`index_phrases`	If enabled, two-term word combinations (shingles) are indexed into a separate field. This allows exact phrase queries (no slop) to run more efficiently, at the expense of a larger index. Note that this works best when stopwords are not removed, as phrases containing stopwords will not use the subsidiary field and will fall back to a standard phrase query. Accepts `true` or `false` (default).
`norms`	Whether field-length should be taken into account when scoring queries. Accepts `true` (default) or `false`.
`position_increment_gap`	The number of fake term position which should be inserted between each element of an array of strings. Defaults to the `position_increment_gap` configured on the analyzer which defaults to `100`. `100` was chosen because it prevents phrase queries with reasonably large slops (less than 100) from matching terms across field values.
`store`	Whether the field value should be stored and retrievable separately from the `_source` field. Accepts `true` or `false` (default).
`search_analyzer`	The `analyzer` that should be used at search time on the `text` field. Defaults to the `analyzer` setting.
`search_quote_analyzer`	The `analyzer` that should be used at search time when a phrase is encountered. Defaults to the `search_analyzer` setting.
`similarity`	Which scoring algorithm or similarity should be used. Defaults to `BM25`.
`term_vector`	Whether term vectors should be stored for the field. Defaults to `no`.
`meta`	Metadata about the field.

`fielddata` mapping parameter

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text fields are searchable by default, but by default are not available for aggregations, sorting, or scripting. If you try to sort, aggregate, or access values from a script on a text field, you will see this exception:

Fielddata is disabled on text fields by default. Set fielddata=true on your_field_name in order to load fielddata in memory by uninverting the inverted index. Note that this can however use significant memory.

Field data is the only way to access the analyzed tokens from a full text field in aggregations, sorting, or scripting. For example, a full text field like New York would get analyzed as new and york. To aggregate on these tokens requires field data.

Before enabling fielddata

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It usually doesn’t make sense to enable fielddata on text fields. Field data is stored in the heap with the field data cache because it is expensive to calculate. Calculating the field data can cause latency spikes, and increasing heap usage is a cause of cluster performance issues.

Most users who want to do more with text fields use multi-field mappings by having both a text field for full text searches, and an unanalyzed keyword field for aggregations, as follows:

PUT my-index-000001
{
  "mappings": {
    "properties": {
      "my_field": { 
        "type": "text",
        "fields": {
          "keyword": { 
            "type": "keyword"
          }
        }
      }
    }
  }
}

	Use the `my_field` field for searches.
	Use the `my_field.keyword` field for aggregations, sorting, or in scripts.

Enabling fielddata on `text` fields

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You can enable fielddata on an existing text field using the PUT mapping API as follows:

PUT my-index-000001/_mapping
{
  "properties": {
    "my_field": { 
      "type":     "text",
      "fielddata": true
    }
  }
}

The mapping that you specify for my_field should consist of the existing mapping for that field, plus the fielddata parameter.

`fielddata_frequency_filter` mapping parameter

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Fielddata filtering can be used to reduce the number of terms loaded into memory, and thus reduce memory usage. Terms can be filtered by frequency:

The frequency filter allows you to only load terms whose document frequency falls between a min and max value, which can be expressed an absolute number (when the number is bigger than 1.0) or as a percentage (eg 0.01 is 1% and 1.0 is 100%). Frequency is calculated per segment. Percentages are based on the number of docs which have a value for the field, as opposed to all docs in the segment.

Small segments can be excluded completely by specifying the minimum number of docs that the segment should contain with min_segment_size:

PUT my-index-000001
{
  "mappings": {
    "properties": {
      "tag": {
        "type": "text",
        "fielddata": true,
        "fielddata_frequency_filter": {
          "min": 0.001,
          "max": 0.1,
          "min_segment_size": 500
        }
      }
    }
  }
}

« Sparse vector data type Token count field type »

Text field type

Text field type

Use a field as both text and keyword

Parameters for text fields

fielddata mapping parameter

Before enabling fielddata

Enabling fielddata on text fields

fielddata_frequency_filter mapping parameter

`fielddata` mapping parameter

Enabling fielddata on `text` fields

`fielddata_frequency_filter` mapping parameter