ElasticSearch Snowball token filter

Snowball token filter

使用除梗器,對單詞進行除梗的過濾器。語言參數可以控制除梗器，有如下的語言可供選擇：
Armenian, Basque, Catalan, Danish, Dutch, English, Finnish, French, German, German2, Hungarian, Italian, Kp, Lithuanian, Lovins, Norwegian, Porter, Portuguese, Romanian, Russian, Spanish, Swedish, Turkish.

例如:

PUT /my_index
{
    "settings": {
        "analysis" : {
            "analyzer" : {
                "my_analyzer" : {
                    "tokenizer" : "standard",
                    "filter" : ["lowercase", "my_snow"]
                }
            },
            "filter" : {
                "my_snow" : {
                    "type" : "snowball",
                    "language" : "Lovins"
                }
            }
        }
    }
}

snowball token filter ，它可以把 sing/ sings / singing 都轉化詞幹 sing。不管用戶搜 sing、sings、singing， 他的搜索結果都是基於「sing」這個term，所得的結果集都一樣。