Elasticsearch More Like This 搜索
Elasticsearch 封装好了More Like This 搜索功能, 用来基于给定的某个或某组文档, 返回与之相似的文档. 语法如下:
{
"more_like_this" : {
"fields" : ["title", "description"],
"docs" : [
{
"_index" : "imdb",
"_type" : "movies",
"_id" : "1"
},
{
"_index" : "imdb",
"_type" : "movies",
"_id" : "2"
}],
"min_term_freq" : 1,
"max_query_terms" : 12
}
}
结合 Rails 例子:
@post = Post.last
query = {:query=>{:more_like_this=>{docs:[{_index: 'posts',_type: 'post', _id: @post.id}], :min_term_freq=>1, :min_doc_freq=>1}}}
records = Post.search(query).records
这个查询的参数有三个,分别是 Document Input Parameters, Term Selection Parametersedit, Query Formation Parameters
Document Input Parameters 是必须有的查询参数, 可以是 docs, ids 或者 like_text之一.
Term Selection Parametersedit 可以是 max_query_terms, min_term_freq, min_doc_freq, max_doc_freq, min_word_length, max_word_length, stop_words, analyzer
Query Formation Parameters 可以是 minimum_should_match, boost_terms, include, boost
相关释义文档写的还是挺清楚的.