# Need information on Latency on Query analytics

**URL:** https://forums.percona.com/t/need-information-on-latency-on-query-analytics/5510
**Category:** PMM 1.x
**Created:** [March 28, 2017, 6:58am UTC](https://forums.percona.com/t/need-information-on-latency-on-query-analytics/5510 "2017-03-28T06:58:21Z")
**Posts on this page:** 4
**Page:** 1

<div class="post-metadata">

### Author: ![naveenjv](https://avatars.discourse-cdn.com/v4/letter/n/a4c791/32.png) [@naveenjv](https://forums.percona.com/u/naveenjv)
#### Post date: [March 28, 2017, 6:58am UTC](https://forums.percona.com/t/need-information-on-latency-on-query-analytics/5510/1 "2017-03-28T06:58:21Z")

</div>

Hello Experts,

I am MS SQL Developer and new to MySQL. I came across Percona Monitoring and Management tool → Query Analytics. There is a column called “Latency” and “Load”. Can any experts explain me this please?

Regards,  
Naveen

---

<div class="post-metadata">

### Author: ![Mykola](https://sea1.discourse-cdn.com/flex019/user_avatar/forums.percona.com/mykola/32/30_2.png) [@Mykola](https://forums.percona.com/u/Mykola)
#### Post date: [March 28, 2017, 9:20am UTC](https://forums.percona.com/t/need-information-on-latency-on-query-analytics/5510/2 "2017-03-28T09:20:57Z")

</div>

Hi naveenjv,

Query Analytics joins statistics for similar queries into query class.  
we have several metrics for each query class:  
[LIST]  
[_]query\_time\_sum - summary of all query times for class  
[_]query\_time\_max - maximal query times for class  
[_]query\_time\_avg - average query times for class  
[_]query\_time\_min - minimal query times for class  
[/LIST]  
So, in Query Analytics interface you can see the following values:

Load = SUM(query\_time\_sum) / time\_range  
Latency Max = MAX(query\_time\_max)  
Latency Avg = AVG(query\_time\_avg)  
Latency Min = MIN(query\_time\_min)

---

<div class="post-metadata">

### Author: ![naveenjv](https://avatars.discourse-cdn.com/v4/letter/n/a4c791/32.png) [@naveenjv](https://forums.percona.com/u/naveenjv)
#### Post date: [April 3, 2017, 7:33am UTC](https://forums.percona.com/t/need-information-on-latency-on-query-analytics/5510/3 "2017-04-03T07:33:51Z")

</div>

Thanks Mykola for the information. But I am not clear what does ‘query class’ means?

I have an update Mysql query which takes around 0.002 secs if I execute directly in MySQL window, but Query analytics windows show latency as 3.02 secs.  
What does this actually means? Do I need to ignore this or need to take some preventive actions?

Also, I have one select query which shows up Load as ‘1.49 k (16.02%)’, how do I interpret this?

Thanks in advance.  
Naveen J V

---

<div class="post-metadata">

### Author: ![Mykola](https://sea1.discourse-cdn.com/flex019/user_avatar/forums.percona.com/mykola/32/30_2.png) [@Mykola](https://forums.percona.com/u/Mykola)
#### Post date: [April 4, 2017, 12:24am UTC](https://forums.percona.com/t/need-information-on-latency-on-query-analytics/5510/4 "2017-04-04T00:24:54Z")

</div>

Hi naveenjv,

> [@](#):
>
> what does ‘query class’ means?

application can run very many queries, but usually these queries has difference only in passed data.  
for example database can receive billions queries like the following

```auto
SELECT value FROM table WHERE key=?

```

each request will have unique key (instead of “?”), so all of queries are unique,  
But it is only one query class because difference is only in passed data.

> [@](#):
>
> Query analytics windows show latency as 3.02 secs.  
> What does this actually means?

it is maximal query time for query class. It means that this query sometimes can be very-very slow.

> [@](#):
>
> Load as ‘1.49 k (16.02%)’, how do I interpret this?

is means that you database 16.02% of time works only on this query class.  
if you optimize this query you can decrease db load up to 15%