German analyzer
The built-in german analyzer can be applied to a text field using the following command:
PUT /german-index
{
"mappings": {
"properties": {
"content": {
"type": "text",
"analyzer": "german"
}
}
}
}
Stem exclusion
You can use stem_exclusion with this language analyzer using the following command:
PUT index_with_stem_exclusion_german_analyzer
{
"settings": {
"analysis": {
"analyzer": {
"stem_exclusion_german_analyzer": {
"type": "german",
"stem_exclusion": ["Autorität", "Genehmigung"]
}
}
}
}
}
German analyzer internals
The german analyzer is built using the following components:
-
Tokenizer:
standard -
Token filters:
- lowercase
- stop (German)
- keyword
- normalization (German)
- stemmer (German)
Custom German analyzer
You can create a custom German analyzer using the following command:
PUT /german-index
{
"settings": {
"analysis": {
"filter": {
"german_stop": {
"type": "stop",
"stopwords": "_german_"
},
"german_stemmer": {
"type": "stemmer",
"language": "light_german"
},
"german_keywords": {
"type": "keyword_marker",
"keywords": []
}
},
"analyzer": {
"german_analyzer": {
"type": "custom",
"tokenizer": "standard",
"filter": [
"lowercase",
"german_stop",
"german_keywords",
"german_normalization",
"german_stemmer"
]
}
}
}
},
"mappings": {
"properties": {
"content": {
"type": "text",
"analyzer": "german_analyzer"
}
}
}
}
Generated tokens
Use the following request to examine the tokens generated using the analyzer:
POST /german-index/_analyze
{
"field": "content",
"text": "Die Studenten studieren an den deutschen Universitäten. Ihre Nummern sind 123456."
}
The response contains the generated tokens:
{
"tokens": [
{
"token": "student",
"start_offset": 4,
"end_offset": 13,
"type": "<ALPHANUM>",
"position": 1
},
{
"token": "studi",
"start_offset": 14,
"end_offset": 23,
"type": "<ALPHANUM>",
"position": 2
},
{
"token": "deutsch",
"start_offset": 31,
"end_offset": 40,
"type": "<ALPHANUM>",
"position": 5
},
{
"token": "universitat",
"start_offset": 41,
"end_offset": 54,
"type": "<ALPHANUM>",
"position": 6
},
{
"token": "numm",
"start_offset": 61,
"end_offset": 68,
"type": "<ALPHANUM>",
"position": 8
},
{
"token": "123456",
"start_offset": 74,
"end_offset": 80,
"type": "<NUM>",
"position": 10
}
]
}