ElasticSearch 搜索推荐

Term Suggester

"suggest_mode":"missing"  missing 默认选项，不返回精准匹配到的分词结果
"suggest_mode":"popular"  popular 大于等于搜索词频率的返回
"suggest_mode":"always", 不做任何限制"min_doc_freq":2		出现在文档中的次数大于min_doc_freq的才返回,同一文档中多次出现算一次。GET /product/_search
{"suggest": {"desc_suggest": {"text":"手机中的","term":{"field":"desc","suggest_mode":"popular","min_doc_freq":2}}}
}

Completion Suggester

基于内存而非索引（内存消耗大），性能好，只适合前缀搜索
结果精准度高召回率低#添加新字段 设置suggest
PUT /product/_mapping
{"properties": {"desc_sugg": {"type": "text","analyzer": "ik_max_word","fields": {"suggest": {"type": "completion","analyzer": "ik_max_word"}}}}
}#给新字段赋值
POST /product/_update_by_query
{"script": {"source": "ctx._source.desc_sugg=ctx._source.desc","lang": "painless"},"query": {"match_all": {}}
}
# "skip_duplicates":true, 结果去重  
# "fuzziness":2 允许容错数
GET /product/_search
{"suggest": {"desc_suggest": {"prefix": "耳机","completion": {"field": "desc_sugg.suggest","skip_duplicates":true,"fuzzy":{"fuzziness":2}}}}
}

Context Suggester

新增索引
PUT product_suggest
{"mappings": {"properties": {"suggest": {"type": "completion","contexts": [{"name": "place_type","type": "category","path": "tags"},{"name": "localtion","type": "geo","path": "loc","precision": 4}]},"loc":{"type": "geo_point"}}}
}
新增数据
PUT /product_suggest/_doc/1
{"suggest":["hello","word","tremhhh"],"tags":["no","hh"]
}PUT /product_suggest/_doc/2
{"suggest":["hellhho","word","treeemhhh"],"tags":["monely"]
}PUT /product_suggest/_doc/3
{"suggest": ["latlon","word","tremhhh"],"loc": [{"lat": 43.56,"lon": -79.56},{"lat": 49.56,"lon": -59.56}]
}
# "place_type":["no"] 在传入的指定分类中查询
# {"context":"monely","boost":2}  boost增加权重返回结果会排在前面
POST /product_suggest/_search
{"suggest": {"tag_suggest": {"prefix": "he","completion": {"field": "suggest","size":10,"skip_duplicates":true,"contexts":{"place_type":[{"context":"no"},{"context":"monely","boost":2}]}}}}
}
#地理位置查询
POST /product_suggest/_search
{"suggest": {"tag_suggest": {"prefix": "tre","completion": {"field": "suggest","size": 10,"skip_duplicates": true,"contexts": {"localtion": [{"lat": 43.55,"lon": -79.55}]}}}}
}