Each field has a field data type, or field type. This type indicates the kind of data the field contains, such as strings or boolean values, and its intended use. For example, you can index strings to both text
and keyword
fields. However, text
field values are analyzed for full-text search while keyword
strings are left as-is for filtering and sorting.
Field types are grouped by family. Types in the same family support the same search functionality but may have different space usage or performance characteristics.
Currently, the only type family is keyword
, which consists of the keyword
, constant_keyword
, and wildcard
field types. Other type families have only a single field type. For example, the boolean
type family consists of one field type: boolean
.
Common types
binary
: Binary value encoded as a Base64 string.boolean
:true
andfalse
values.- Keywords: The keyword family, including
keyword
,constant_keyword
, andwildcard
. - Numbers: Numeric types, such as
long
anddouble
, used to express amounts. - Dates: Date types, including
date
anddate_nanos
. alias
: Defines an alias for an existing field.
Objects and relational types
object
: A JSON object.flattened
: An entire JSON object as a single field value.nested
: A JSON object that preserves the relationship between its subfields.join
: Defines a parent/child relationship for documents in the same index.
Structured data types
- Range: Range types, such as
long_range
,double_range
,date_range
, andip_range
. ip
: IPv4 and IPv6 addresses.version
: Software versions. Supports Semantic Versioning precedence rules.murmur3
: Compute and stores hashes of values.
Aggregate data types
aggregate_metric_double
: Pre-aggregated metric values.histogram
: Pre-aggregated numerical values in the form of a histogram.
Text search types
text
: Analyzed, unstructured text.annotated-text
: Text containing special markup. Used for identifying named entities.completion
: Used for auto-complete suggestions.search_as_you_type
:text
-like type for as-you-type completion.token_count
: A count of tokens in a text.
Document ranking types
dense_vector
: Records dense vectors of float values.sparse_vector
: Records sparse vectors of float values.rank_feature
: Records a numeric feature to boost hits at query time.rank_features
: Records numeric features to boost hits at query time.
Spatial data types
geo_point
: Latitude and longitude points.geo_shape
: Complex shapes, such as polygons.point
: Arbitrary cartesian points.shape
: Arbitrary cartesian geometries.
Other types
percolator
: Indexes queries written in Query DSL.
Arrays
In Elasticsearch, arrays do not require a dedicated field data type. Any field can contain zero or more values by default, however, all values in the array must be of the same field type. See Arrays.
Multi-fields
It is often useful to index the same field in different ways for different purposes. For instance, a string
field could be mapped as a text
field for full-text search, and as a keyword
field for sorting or aggregations. Alternatively, you could index a text field with the standard
analyzer, the english
analyzer, and the french
analyzer.
This is the purpose of multi-fields. Most field types support multi-fields via the fields
parameter.
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原文出处:elastic
原文链接:https://www.elastic.co/guide/en/elasticsearch/reference/7.x/mapping-types.html#_core_datatypes