<!-- [[proximity-matching]] == Proximity Matching translated by Yang --> ## 模糊匹配 <!-- Standard full-text search with TF/IDF treats documents, or at least each field within a document, as a big _bag of words_.((("proximity matching"))) The `match` query can tell us whether that bag contains our search terms, but that is only part of the story. It can't tell us anything about the relationship between words. --> 一般的全文檢索方式使用 TF/IDF 處理文本或者文本數據中的某個字段內容。將字面切分成很多字、詞(word)建立索引，match查詢用query中的term來匹配索引中的字、詞。match查詢提供了文檔數據中是否包含我們需要的query中的單、詞，但僅僅這樣是不夠的，它無法提供文本中的字詞之間的關系。 <!-- Consider the difference between these sentences: * Sue ate the alligator. * The alligator ate Sue. * Sue never goes anywhere without her alligator-skin purse. A `match` query for `sue alligator` would match all three documents, but it doesn't tell us whether the two words form part of the same idea, or even the same paragraph. --> 舉個例子： * 小蘇吃了鱷魚 * 鱷魚吃了小蘇 * 小蘇去哪兒都帶著的鱷魚皮錢包 用`match`查詢`小蘇 鱷魚`，這三句話都會被命中，但是`tf/idf`并不會告訴我們這兩個詞出現在同一句話里面還是在同一個段落中（僅僅提供這兩個詞在這段文本中的出現頻率） <!-- Understanding how words relate to each other is a complicated problem, and we can't solve it by just using another type of query, but we can at least find words that appear to be related because they appear near each other or even right next to each other. Each document may be much longer than the examples we have presented: `Sue` and `alligator` may be separated by paragraphs of other text. Perhaps we still want to return these documents in which the words are widely separated, but we want to give documents in which the words are close together a higher relevance score. This is the province of _phrase matching_, or _proximity matching_. --> 理解文本中詞語之間的關系是一個很復雜的問題，而且這個問題通過更換query的表達方式是無法解決的。但是我們可以知道兩個詞語在文本中的距離遠近，甚至是否相鄰，這個信息似乎上能一定程度的表達這兩個詞比較相關。 一般的文本可能比我們舉的例子長很多，正如我們提到的：`小蘇`跟`鱷魚`這兩個詞可能分布在文本的不同段落中。我們還是期望能找到這兩個詞分布均勻的文檔，但是我們把這兩個詞距離比較近的文檔賦予更好的相關性權重。 這就是段落匹配（_phrase matching_）或者模糊匹配（_proximity matching_）所做的事情。 <!-- [TIP] ================================================== In this chapter, we are using the same example documents that we used for the <<match-test-data,`match` query>>. ================================================== --> 【**提示** 】 這一章，我們會用之之前在< match-test-data, `match` query >中使用的文檔做例子。