The built-in language analyzers are available globally and don’t need to be configured before being used. They can be specified directly in the field mapping:
PUT /my_index
{
"mappings": {
"blog": {
"properties": {
"title": {
"type": "string",
"analyzer": "english" (1)
}
}
}
}
}
The title
field will use the english
analyzer instead of the default
standard
analyzer.
Of course, by passing text through the english
analyzer, we lose
information:
GET /my_index/_analyze?field=title (1)
I'm not happy about the foxes
Emits token: i’m
, happi
, about
, fox
We can’t tell if the document mentions one fox
or many foxes
; the word
not
is a stopword and is removed, so we can’t tell whether the document is
happy about foxes or not. By using the english
analyzer, we have increased
recall as we can match more loosely, but we have reduced our ability to rank
documents accurately.
To get the best of both worlds, we can use multifields to
index the title
field twice: once with the english
analyzer and once with
the standard
analyzer:
PUT /my_index
{
"mappings": {
"blog": {
"properties": {
"title": { (1)
"type": "string",
"fields": {
"english": { (2)
"type": "string",
"analyzer": "english"
}
}
}
}
}
}
}
The main title
field uses the standard
analyzer.
The title.english
subfield uses the english
analyzer.
With this mapping in place, we can index some test documents to demonstrate how to use both fields at query time:
PUT /my_index/blog/1
{ "title": "I'm happy for this fox" }
PUT /my_index/blog/2
{ "title": "I'm not happy about my fox problem" }
GET /_search
{
"query": {
"multi_match": {
"type": "most_fields", (1)
"query": "not happy foxes",
"fields": [ "title", "title.english" ]
}
}
}
Use the most_fields
query type to match the
same text in as many fields as possible.
Even though neither of our documents contain the word foxes
, both documents
are returned as results thanks to the word stemming on the title.english
field. The second document is ranked as more relevant, because the word not
matches on the title
field.
此处可能存在不合适展示的内容,页面不予展示。您可通过相关编辑功能自查并修改。
如您确认内容无涉及 不当用语 / 纯广告导流 / 暴力 / 低俗色情 / 侵权 / 盗版 / 虚假 / 无价值内容或违法国家有关法律法规的内容,可点击提交进行申诉,我们将尽快为您处理。