Greek analyzer
The built-in greek analyzer can be applied to a text field using the following command:
PUT /greek-index
{
"mappings": {
"properties": {
"content": {
"type": "text",
"analyzer": "greek"
}
}
}
}
Stem exclusion
You can use stem_exclusion with this language analyzer using the following command:
PUT index_with_stem_exclusion_greek_analyzer
{
"settings": {
"analysis": {
"analyzer": {
"stem_exclusion_greek_analyzer": {
"type": "greek",
"stem_exclusion": ["αρχή", "έγκριση"]
}
}
}
}
}
Greek analyzer internals
The greek analyzer is built using the following components:
-
Tokenizer:
standard -
Token filters:
- lowercase
- stop (Greek)
- keyword
- stemmer (Greek)
Custom Greek analyzer
You can create a custom Greek analyzer using the following command:
PUT /greek-index
{
"settings": {
"analysis": {
"filter": {
"greek_stop": {
"type": "stop",
"stopwords": "_greek_"
},
"greek_lowercase": {
"type": "lowercase",
"language": "greek"
},
"greek_stemmer": {
"type": "stemmer",
"language": "greek"
},
"greek_keywords": {
"type": "keyword_marker",
"keywords": []
}
},
"analyzer": {
"greek_analyzer": {
"type": "custom",
"tokenizer": "standard",
"filter": [
"greek_lowercase",
"greek_stop",
"greek_keywords",
"greek_stemmer"
]
}
}
}
},
"mappings": {
"properties": {
"content": {
"type": "text",
"analyzer": "greek_analyzer"
}
}
}
}
Generated tokens
Use the following request to examine the tokens generated using the analyzer:
POST /greek-index/_analyze
{
"field": "content",
"text": "Οι φοιτητές σπουδάζουν στα ελληνικά πανεπιστήμια. Οι αριθμοί τους είναι 123456."
}
The response contains the generated tokens:
{
"tokens": [
{
"token": "φοιτητ",
"start_offset": 3,
"end_offset": 11,
"type": "<ALPHANUM>",
"position": 1
},
{
"token": "σπουδαζ",
"start_offset": 12,
"end_offset": 22,
"type": "<ALPHANUM>",
"position": 2
},
{
"token": "στα",
"start_offset": 23,
"end_offset": 26,
"type": "<ALPHANUM>",
"position": 3
},
{
"token": "ελλην",
"start_offset": 27,
"end_offset": 35,
"type": "<ALPHANUM>",
"position": 4
},
{
"token": "πανεπιστημ",
"start_offset": 36,
"end_offset": 48,
"type": "<ALPHANUM>",
"position": 5
},
{
"token": "αριθμ",
"start_offset": 53,
"end_offset": 60,
"type": "<ALPHANUM>",
"position": 7
},
{
"token": "τ",
"start_offset": 61,
"end_offset": 65,
"type": "<ALPHANUM>",
"position": 8
},
{
"token": "123456",
"start_offset": 72,
"end_offset": 78,
"type": "<NUM>",
"position": 10
}
]
}