Elasticsearch是否保持多值字段的顺序? [英] Does Elasticsearch keep an order of multi-value fields?

问题描述

Elasticsearch是否保留多值字段的顺序?

Does Elasticsearch keep an order of multi-value fields?

即如果我在字段中输入了以下值:

I.e. if I've put following values into fields:

{
    "values": ["one", "two", "three"],
    "values_original": ["1", "2", "3"]
}

(鉴于未分析字段)

我可以确定列表的内容将始终按照我放置在列表中的顺序返回吗?

Can I be sure that the contents of lists will always be returned in the same order I put it there?

在上面的示例中，我想确保值"中第一个位置上的一个"始终与"values_original"等中的"1"相对应.

In the example above, I want to make sure that "one" on first position in "values" will always correspond to "1" in "values_original" etc.

我也可以将其保留为嵌套对象，即

I could keep it also as nested objects, i.e.

{
    "values": [
        {"original": "1", "new": "one"}, 
        {"original":"2", "new":"two"},
        {"original":"3","new":"three"}
    ]
}

但我想避免开销.

如果可以保证保留多值字段中的值顺序，那么我保留两个并行多值字段的方法将起作用.

If it is guaranteed that order of values in multi-value field is preserved, then my approach of keeping two parallel multi-valued fields will work.

推荐答案

Elasticsearch-权威指南说:

当您从Elasticsearch取回文档时，任何数组的顺序都将与索引该文档时的顺序相同.您返回的_source字段包含与索引相同的JSON文档.

When you get a document back from Elasticsearch, any arrays will be in the same order as when you indexed the document. The _source field that you get back contains exactly the same JSON document that you indexed.

但是，数组被索引为可搜索的，成为无序的多值字段.在搜索时，您不能引用第一个元素"或最后一个元素".而是将数组视为一袋值.

However, arrays are indexed—made searchable—as multivalue fields, which are unordered. At search time, you can’t refer to "the first element" or "the last element." Rather, think of an array as a bag of values.

因此对于存储的字段似乎保留了顺序，对于索引的字段则没有保留.

So it seems that for stored fields order is preserved, for indexed fields it's not.

这篇关于Elasticsearch是否保持多值字段的顺序?的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！