关于elasticsearch的先聚合和过滤、先过滤再聚合的详解
对于elasticsearch的聚合和过滤，他的结果并不会受到你写的顺序而影响。换句话说就是你无论是在聚合语句的前面写过滤条件，还是在过滤语句后面写过滤条件都不会影响他的结果。 他都会先过滤再聚合和关系数据库一样先where后group by。
但是如果你想过滤条件不影响聚合(agg)结果，而只是改变hits结果；可以使用setPostFilter() 这个方法
eg：全部数据
代码：
SearchResponse response = null;
SearchRequestBuilder responsebuilder = client.prepareSearch("company")
.setTypes("employee").setFrom(0).setSize(250);
AggregationBuilder aggregation = AggregationBuilders
.terms("agg")
.field("age") ;
response = responsebuilder
.addAggregation(aggregation)
.setExplain(true).execute().actionGet();
SearchHits hits = response.getHits();
Terms agg = response.getAggregations().get("agg");
结果 ： 仅聚合结果不过滤（注意看hits和agg里的结果）
{
"took":100,
"timed_out":false,
"_shards":{
"total":5,
"successful":5,
"failed":0
},
"hits":{
"total":7,
"max_score":1,
"hits":[
{
"_shard":1,
"_node":"fvp3NBT5R5i6CqN3y2LU4g",
"_index":"company",
"_type":"employee",
"_id":"5",
"_score":1,
"_source":{
"name":"Fresh",
"age":22
},
"_explanation":Object{...}
},
{
"_shard":1,
"_node":"fvp3NBT5R5i6CqN3y2LU4g",
"_index":"company",
"_type":"employee",
"_id":"10",
"_score":1,
"_source":{
"name":"Henrry",
"age":30
},
"_explanation":Object{...}
},
{
"_shard":1,
"_node":"fvp3NBT5R5i6CqN3y2LU4g",
"_index":"company",
"_type":"employee",
"_id":"9",
"_score":1,
"_source":{
"address":{
"country":"china",
"province":"jiangsu",
"city":"nanjing",
"area":{
"pos":"10001"
}
}
},
"_explanation":Object{...}
},
{
"_shard":2,
"_node":"fvp3NBT5R5i6CqN3y2LU4g",
"_index":"company",
"_type":"employee",
"_id":"2",
"_score":1,
"_source":{
"address":{
"country":"china",
"province":"jiangsu",
"city":"nanjing"
},
"name":"jack_1",
"age":19,
"join_date":"2016-01-01"
},
"_explanation":Object{...}
},
{
"_shard":2,
"_node":"fvp3NBT5R5i6CqN3y2LU4g",
"_index":"company",
"_type":"employee",
"_id":"4",
"_score":1,
"_source":{
"name":"willam",
"age":18
},
"_explanation":Object{...}
},
{
"_shard":2,
"_node":"fvp3NBT5R5i6CqN3y2LU4g",
"_index":"company",
"_type":"employee",
"_id":"6",
"_score":1,
"_source":{
"name":"Avivi",
"age":30
},
"_explanation":Object{...}
},
{
"_shard":4,
"_node":"K7qK1ncMQUuIe0K6VSVMJA",
"_index":"company",
"_type":"employee",
"_id":"3",
"_score":1,
"_source":{
"address":{
"country":"china",
"province":"shanxi",
"city":"xian"
},
"name":"marry",
"age":35,
"join_date":"2015-01-01"
},
"_explanation":Object{...}
}
]
},
"aggregations":{
"agg":{
"doc_count_error_upper_bound":0,
"sum_other_doc_count":0,
"buckets":[
{
"key":30,
"doc_count":2
},
{
"key":18,
"doc_count":1
},
{
"key":19,
"doc_count":1
},
{
"key":22,
"doc_count":1
},
{
"key":35,
"doc_count":1
}
]
}
}
}
1、setQuery() 写在前面
代码：
SearchResponse response = null;
SearchRequestBuilder responsebuilder = client.prepareSearch("company")
.setTypes("employee").setFrom(0).setSize(250);
AggregationBuilder aggregation = AggregationBuilders
.terms("agg")
.field("age") ;
response = responsebuilder
.setQuery(QueryBuilders.rangeQuery("age").gt(30).lt(40))
.addAggregation(aggregation)
.setExplain(true).execute().actionGet();
SearchHits hits = response.getHits();
Terms agg = response.getAggregations().get("agg");
结果：
{
"took":538,
"timed_out":false,
"_shards":{
"total":5,
"successful":5,
"failed":0
},
"hits":{
"total":1,
"max_score":1,
"hits":[
{
"_shard":4,
"_node":"anlkGjjuQ0G6DODpZgiWrQ",
"_index":"company",
"_type":"employee",
"_id":"3",
"_score":1,
"_source":{
"address":{
"country":"china",
"province":"shanxi",
"city":"xian"
},
"name":"marry",
"age":35,
"join_date":"2015-01-01"
},
"_explanation":Object{...}
}
]
},
"aggregations":{
"agg":{
"doc_count_error_upper_bound":0,
"sum_other_doc_count":0,
"buckets":[
{
"key":35,
"doc_count":1
}
]
}
}
}
2、setQuery() 写在后面
代码：
SearchResponse response = null;
SearchRequestBuilder responsebuilder = client.prepareSearch("company")
.setTypes("employee").setFrom(0).setSize(250);
AggregationBuilder aggregation = AggregationBuilders
.terms("agg")
.field("age") ;
response = responsebuilder
.addAggregation(aggregation)
.setQuery(QueryBuilders.rangeQuery("age").gt(30).lt(40)
.setExplain(true).execute().actionGet();
SearchHits hits = response.getHits();
Terms agg = response.getAggregations().get("agg");
结果：
"took":538,
"timed_out":false,
"_shards":{
"total":5,
"successful":5,
"failed":0
},
"hits":{
"total":1,
"max_score":1,
"hits":[
{
"_shard":4,
"_node":"anlkGjjuQ0G6DODpZgiWrQ",
"_index":"company",
"_type":"employee",
"_id":"3",
"_score":1,
"_source":{
"address":{
"country":"china",
"province":"shanxi",
"city":"xian"
},
"name":"marry",
"age":35,
"join_date":"2015-01-01"
},
"_explanation":Object{...}
}
]
},
"aggregations":{
"agg":{
"doc_count_error_upper_bound":0,
"sum_other_doc_count":0,
"buckets":[
{
"key":35,
"doc_count":1
}
]
}
}
}
3、setPostFilter() 在聚合.aggAggregation()方法后
代码：
SearchResponse response = null;
SearchRequestBuilder responsebuilder = client.prepareSearch("company")
.setTypes("employee").setFrom(0).setSize(250);
AggregationBuilder aggregation = AggregationBuilders
.terms("agg")
.field("age") ;
response = responsebuilder
.addAggregation(aggregation)
.setPostFilter(QueryBuilders.rangeQuery("age").gt(30).lt(40))
.setExplain(true).execute().actionGet();
SearchHits hits = response.getHits();
Terms agg = response.getAggregations().get("agg");
结果：
{
"took":7,
"timed_out":false,
"_shards":{
"total":5,
"successful":5,
"failed":0
},
"hits":{
"total":1,
"max_score":1,
"hits":[
{
"_shard":4,
"_node":"fvp3NBT5R5i6CqN3y2LU4g",
"_index":"company",
"_type":"employee",
"_id":"3",
"_score":1,
"_source":{
"address":{
"country":"china",
"province":"shanxi",
"city":"xian"
},
"name":"marry",
"age":35,
"join_date":"2015-01-01"
},
"_explanation":Object{...}
}
]
},
"aggregations":{
"agg":{
"doc_count_error_upper_bound":0,
"sum_other_doc_count":0,
"buckets":[
{
"key":30,
"doc_count":2
},
{
"key":18,
"doc_count":1
},
{
"key":19,
"doc_count":1
},
{
"key":22,
"doc_count":1
},
{
"key":35,
"doc_count":1
}
]
}
}
}
4、setPostFilter() 在聚合.aggAggregation()方法前
代码：
SearchResponse response = null;
SearchRequestBuilder responsebuilder = client.prepareSearch("company")
.setTypes("employee").setFrom(0).setSize(250);
AggregationBuilder aggregation = AggregationBuilders
.terms("agg")
.field("age") ;
response = responsebuilder
.setPostFilter(QueryBuilders.rangeQuery("age").gt(30).lt(40))
.addAggregation(aggregation)
.setExplain(true).execute().actionGet();
SearchHits hits = response.getHits();
Terms agg = response.getAggregations().get("agg");
结果：
{
"took":5115,
"timed_out":false,
"_shards":{
"total":5,
"successful":5,
"failed":0
},
"hits":{
"total":1,
"max_score":1,
"hits":[
{
"_shard":4,
"_node":"b8cNIO5cQr2MmsnsuluoNQ",
"_index":"company",
"_type":"employee",
"_id":"3",
"_score":1,
"_source":{
"address":{
"country":"china",
"province":"shanxi",
"city":"xian"
},
"name":"marry",
"age":35,
"join_date":"2015-01-01"
},
"_explanation":Object{...}
}
]
},
"aggregations":{
"agg":{
"doc_count_error_upper_bound":0,
"sum_other_doc_count":0,
"buckets":[
{
"key":30,
"doc_count":2
},
{
"key":18,
"doc_count":1
},
{
"key":19,
"doc_count":1
},
{
"key":22,
"doc_count":1
},
{
"key":35,
"doc_count":1
}
]
}
}
}
总结：
可以从运行的结果很好的看出无论是setPostFilter()还是setQuery()，它放在那的顺序并不会影响他的结果。更可以看出setQuery()这个方法的过滤条件不仅会影响它的hits的结果还会影响他的聚合（agg）结果。然而对于setPostFilter()这个方法，它只会影响hits的结果，并不会影响它的聚合（agg）结果。