33 lines
1.1 KiB
Plaintext
33 lines
1.1 KiB
Plaintext
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[[mapping-boost-field]]
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=== `_boost`
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Boosting is the process of enhancing the relevancy of a document or
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field. Field level mapping allows to define explicit boost level on a
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specific field. The boost field mapping (applied on the
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<<mapping-root-object-type,root object>>) allows
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to define a boost field mapping where *its content will control the
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boost level of the document*. For example, consider the following
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mapping:
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[source,js]
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--------------------------------------------------
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{
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"tweet" : {
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"_boost" : {"name" : "my_boost", "null_value" : 1.0}
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}
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}
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--------------------------------------------------
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The above mapping defines mapping for a field named `my_boost`. If the
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`my_boost` field exists within the JSON document indexed, its value will
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control the boost level of the document indexed. For example, the
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following JSON document will be indexed with a boost value of `2.2`:
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[source,js]
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--------------------------------------------------
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{
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"my_boost" : 2.2,
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"message" : "This is a tweet!"
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}
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--------------------------------------------------
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