如何建立索引，以便文本搜索和排序使用索引? [英] How to index so that text search and sort use the index?

问题描述

我有一个mongoengine文档，需要进行文本字段搜索然后进行排序.我设法创建了文本索引，但是排序操作非常慢.我需要一个建议来如何完全索引我的查询:

I have a mongoengine document that needs to have a text field search then be sorted. I managed to create the text index, but the sorting operation is comming by very slow. I need a suggestion how to fully index my query:

class MyDoc(Document):
    meta = {
        'collection': 'my_doc',
        'index_background': True,
        'indexes': [
            '-sort_field',
            {
                'fields': ['$text_field'],
                'default_language': 'portuguese',
            }
        ],
    }
    text_field = StringField()
    sort_field = DateTimeField()

MyDoc.objects.search_text('some text').sort(['-sort_field'])

推荐答案

您不能将文本索引与另一个索引一起用于排序.您可以使用 {"field":1，"t":"text"} 这样的复合索引，并将该索引用于 field 上的相等匹配和文本搜索，但是否则，文本索引不能作为复合索引的一部分.为什么要进行文本搜索然后在另一个字段上排序?这是一个不寻常的用例.返回少量文档(例如返回按日期排序的匹配结果页面)应该很好.

You can't use a text index with another index for the sort. You can have a compound index like { "field" : 1, "t" : "text" } and use the index for equality matches on field and text searches, but otherwise text indexes don't work as part of a compound index. Why do you want to do a text search and then sort on another field? It's a slightly unusual use case. It should be fine for returning small numbers of documents, like for returning a page of matching results sorted by date.

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