Index not improve speed in couchbase 4.5

SQL++
1

I have below query

SELECT day,count(DISTINCT campaignId) campaigns
FROM Inheritx use index(daily_type_1)
where _type='DailyCampaignUsage'
group by day

I have below index

 `CREATE INDEX `daily_type_1` ON `Inheritx` 
(`_type`,`day`,(distinct (`campaignId`))) WHERE (`_type` = "DailyCampaignUsage")`

it is taking 3s and I habe 52k data whare _type= “DailyCampaignUsage”

how I Can improve it’s speed ?

2

@krishn, please see: COUNT and GROUP Faster With N1QL - DZone