尽管我们之前已经涉及了查询DSL，然而实际上存在两种DSL：查询DSL（query DSL）和过滤DSL（filter DSL）。

过滤器（filter）通常用于过滤文档的范围，比如某个字段是否属于某个类型，或者是属于哪个时间区间

* 创建日期是否在2014-2015年间？

* status字段是否为success？

* 包含run单词，如果包含这些单词：runs、running、jog、sprint，也被视为包含run单词

* 包含quick、brown、fox。这些词越接近，这份文档的相关性就越高

查询器会计算出每份文档对于某次查询有多相关（relevant），然后分配文档一个相关性分数：_score。而这个分数会被用来对匹配了的文档进行相关性排序。相关性概念十分适合全文搜索（full-text search），这个很难能给出完整、“正确”答案的领域。

#blog:  http://xiaorui.cc
{"size": 1,"query": { "bool": { "must": [ { "terms": { "keyword": [ "手机", "iphone" ] } }, { "range": { "cdate": { "gt": "2015-11-09T11:00:00" } } } ] } } } { "took": 51, "timed_out": false, "_shards": { "total": 30, "successful": 30, "failed": 0 }, "hits": { "total": 6818, "max_score": 0, "hits": [] } }

#blog:  http://xiaorui.cc
{"size":1,"query":{ "bool":{ "must":[ { "terms":{ "keyword":[ "手机", "iphone" ] } }, { "range":{ "cdate":{ "gt":"2015-11-09T11:00:00" } } } ] } } } { "took":51, "timed_out":false, "_shards":{ "total":30, "successful":30, "failed":0 }, "hits":{ "total":6818, "max_score":0, "hits":[] } } 

#blog: xiaorui.cc
{"size": 0,"filter": {"bool": { "must": [ { "terms": { "keyword": [ "手机", "iphone" ] } }, { "range": { "cdate": { "gt": "2015-11-09T11:00:00" } } } ] } } } { "took": 145, "timed_out": false, "_shards": { "total": 30, "successful": 30, "failed": 0 }, "hits": { "total": 6804, "max_score": 0, "hits": [] } }<span style="font-size:13.2px;line-height:1.5;"></span>

#blog: xiaorui.cc
{"size":0,"filter":{"bool":{"must":[ { "terms":{ "keyword":[ "手机", "iphone" ] } }, { "range":{ "cdate":{ "gt":"2015-11-09T11:00:00" } } } ] } } } { "took":145, "timed_out":false, "_shards":{ "total":30, "successful":30, "failed":0 }, "hits":{ "total":6804, "max_score":0, "hits":[] } }<spanstyle="font-size:13.2px;line-height:1.5;"></span>