Hi all,
I am implementing "did you mean" technology using Elasticsearch. After doing some research I found out, phrase suggesters is designed only for this purpose. But I am facing some issues with it.
My mapping document:
{
"settings": {
"index": {
"number_of_shards": 1,
"analysis": {
"analyzer": {
"trigram": {
"type": "custom",
"tokenizer": "standard",
"filter": ["standard", "shingle"]
},
"reverse": {
"type": "custom",
"tokenizer": "standard",
"filter": ["standard", "reverse"]
}
},
"filter": {
"shingle": {
"type": "shingle",
"min_shingle_size": 2,
"max_shingle_size": 3
}
}
}
}
},
"mappings": {
"test": {
"properties": {
"title": {
"type": "text",
"fields": {
"trigram": {
"type": "text",
"analyzer": "trigram"
},
"reverse": {
"type": "text",
"analyzer": "reverse"
}
}
}
}
}
}
}
My document is :
{"title": "nobel prize"}
My search query is:
{
"suggest": {
"text": "noble prze",
"simple_phrase": {
"phrase": {
"field": "title.trigram",
"size": 1,
"gram_size": 3,
"direct_generator": [ {
"field": "title.trigram",
"suggest_mode": "always"
} ],
"highlight": {
"pre_tag": "<em>",
"post_tag": "</em>"
}
}
}
}
}
The query works fine if there is mismatch with only one character in the text to be searched. Otherwise the phrase suggested corrects only one character.
The output is:
{
"took": 6,
"timed_out": false,
"_shards": {
"total": 1,
"successful": 1,
"skipped": 0,
"failed": 0
},
"hits": {
"total": 0,
"max_score": 0,
"hits": []
},
"suggest": {
"simple_phrase": [
{
"text": "noble prze",
"offset": 0,
"length": 10,
"options": [
{
"text": "nobel prze",
"highlighted": "<em>nobel</em> prze",
"score": 0.16992487
}
]
}
]
}
}