28 lines
964 B
Plaintext
28 lines
964 B
Plaintext
[[mapping-parent-field]]
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=== `_parent`
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The parent field mapping is defined on a child mapping, and points to
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the parent type this child relates to. For example, in case of a `blog`
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type and a `blog_tag` type child document, the mapping for `blog_tag`
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should be:
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[source,js]
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--------------------------------------------------
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{
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"blog_tag" : {
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"_parent" : {
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"type" : "blog"
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}
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}
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}
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--------------------------------------------------
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The mapping is automatically stored and indexed (meaning it can be
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searched on using the `_parent` field notation).
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==== Field data loading
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Contrary to other fields the fielddata loading is not `lazy`, but `eager`. The reason for this is that when this
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field has been enabled it is going to be used in parent/child queries, which heavily relies on field data to perform
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efficiently. This can already be observed during indexing after refresh either automatically or manually has been executed.
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