电商网站商品管理（三）group by+avg+sort 等聚合分析

GET /ecommerce/_search{  "aggs":{    "group_by_tags":{      "terms": {"field":"tags"}    }  }}
{  "error" : {    "root_cause" : [      {        "type" : "illegal_argument_exception",        "reason" : "Text fields are not optimised for operations that require per-document field data like aggregations and sorting, so these operations are disabled by default. Please use a keyword field instead. Alternatively, set fielddata=true on [tags] in order to load field data by uninverting the inverted index. Note that this can use significant memory."      }    ],    "type" : "search_phase_execution_exception",    "reason" : "all shards failed",    "phase" : "query",    "grouped" : true,...

POST ecommerce/_mapping{  "properties":{    "tags":{      "type":"text",      "fielddata":true    }  }}
GET ecommerce/_search{  "size":0,  "aggs":{    "all_tags":{      "terms":{ "field":"tags" }    }  }}
{  "took" : 1,  "timed_out" : false,  "_shards" : {    "total" : 1,    "successful" : 1,    "skipped" : 0,    "failed" : 0  },  "hits" : {    "total" : {      "value" : 6,      "relation" : "eq"    },    "max_score" : null,    "hits" : [ ]  },  "aggregations" : {    "all_tags" : {      "doc_count_error_upper_bound" : 0,      "sum_other_doc_count" : 0,      "buckets" : [        {          "key" : "fangzhu",          "doc_count" : 2        },        ...

GET ecommerce/_search{  "size":0,  "query":{    "match":{      "name":"yagao"    }  },  "aggs":{    "all_tags":{      "terms":{        "field":"tags"      }    }  }}

GET ecommerce/_search{  "size":0,  "aggs":{    "group_by_tags":{      "terms":{"field":"tags"},      "aggs":{        "avg_price":{          "avg":{"field":"price"}        }      }    }  }}
{  "took" : 103,  "timed_out" : false,  "_shards" : {    "total" : 1,    "successful" : 1,    "skipped" : 0,    "failed" : 0  },  "hits" : {    "total" : {      "value" : 6,      "relation" : "eq"    },    "max_score" : null,    "hits" : [ ]  },  ...

GET ecommerce/_search{  "size":0,  "aggs":{    "all_tags":{      "terms":{        "field":"tags",         "order":{"avg_price":"desc"}      },      "aggs":{        "avg_price":{          "avg":{"field":"price"}        }      }    }  }}
{  "took" : 119,  "timed_out" : false,  "_shards" : {    "total" : 1,    "successful" : 1,    "skipped" : 0,    "failed" : 0  },  "hits" : {    "total" : {      "value" : 6,      "relation" : "eq"    },    "max_score" : null,    "hits" : [ ]  },  ...

GET ecommerce/_search{  "size":0,  "aggs":{    "group_by_price":{      "range":{        "field":"price",        "ranges":[          {"from":0, "to":20},           {"from":20, "to":40},          {"from":40, "to":60}        ]      },      "aggs":{        "group_by_tags":{          "terms":{            "field":"tags"          },          "aggs":{            "average_price":{              "avg":{                "field":"price"              }            }          }        }      }    }  }}
{  "took" : 62,  "timed_out" : false,  "_shards" : {    "total" : 1,    "successful" : 1,    "skipped" : 0,    "failed" : 0  },  "hits" : {    "total" : {      "value" : 6,      "relation" : "eq"    },    "max_score" : null,    "hits" : [ ]  },  "aggregations" : {    "group_by_price" : {      "buckets" : [        {          "key" : "0.0-20.0",          "from" : 0.0,          "to" : 20.0,          "doc_count" : 0,          "group_by_tags" : {            "doc_count_error_upper_bound" : 0,            "sum_other_doc_count" : 0,            "buckets" : [ ]          }        },...