文档结构：

Spcode SpnameConsignidConsnameRegionRegionnameServiceidServicenameSrctermidLogtime

#SQL#天分组SELECT Spcode, Spname, Consignid, Consname, Region, Regionname, Serviceid, Servicename, Srctermid FROM mo_log_201208 WHERE Logtime > "20120823" AND Logtime < "20120824" GROUP BY Spcode, Spname, Consignid, Consname, Region, Regionname, Serviceid, Servicename

#MongoDB#天分组res = db.runCommand({	mapreduce:'mo_log_201208',	query:{Logtime:{$gte:'20120823', $lte:'20120824'}},	map:function() {		emit({Spcode:this.Spcode, Spname:this.Spname,                 Consignid:this.Consignid, Consname:this.Consname,                 Region:this.Region, Regionname:this.Regionname,                 Serviceid:this.Serviceid,                    Servicename:this.Servicename,                 Srctermid:this.Srctermid}, {count:1});	},	reduce:function(key, value) {		var ret = {count:0};		ret.count++;		return ret;	},	out:'tmp_mo_spcode_consignid_region_serviceid_201208_1',	verbose:true})

#SQL#月分组SELECT Spcode, Spname, Consignid, Consname, Region, Regionname, Serviceid, Servicename, Srctermid FROM mo_log_201208 GROUP BY Spcode, Spname, Consignid, Consname, Region, Regionname, Serviceid, Servicename

#MongoDB#月分组res = db.runCommand({	mapreduce:'mo_log_201208',	map:function() {		emit({Spcode:this.Spcode, Spname:this.Spname,                 Consignid:this.Consignid, Consname:this.Consname,                 Region:this.Region, Regionname:this.Regionname,                 Serviceid:this.Serviceid, Servicename:this.Servicename,                 Srctermid:this.Srctermid}, {count:1});	},	reduce:function(key, value) {		var ret = {count:0};		ret.count++;		return ret;	},	out:'tmp_mo_spcode_consignid_region_serviceid_201208',	verbose:true})

 >随着每天数据量的不断增长, 月分组的执行时间会不断的增加~~

 >为了减少重复的分组操作, 降低分组时间, 用天分组的数据来迭代月分组的数据

#MongoDBres = db.runCommand({	mapreduce:'mo_log_201208',	query:{Logtime:{$gte:'20120823', $lte:'20120824'}},	map:function() {		emit({Spcode:this.Spcode, Spname:this.Spname,         Consignid:this.Consignid, Consname:this.Consname,         Region:this.Region, Regionname:this.Regionname,         Serviceid:this.Serviceid, Servicename:this.Servicename,         Srctermid:this.Srctermid}, {count:1});	},	reduce:function(key, value) {		var ret = {count:0};		ret.count++;		return ret;	},	finalize:function(key, value){		db.tmp_mo_spcode_consignid_region_serviceid_201208.insert({"_id":key, "value":value});		return value;	},	out:'tmp_mo_spcode_consignid_region_serviceid_201208_1',	verbose:true})

>Mongodb缺省的主键是_id, 在使用insert或者save的时候, 不会产生重复数据