How HoldTime countes in Call_Type_SG_Interval table

[Malen]

Hello, All.

I have two tables Call_Type_SG_Interval and Agent_Skill_Group_Interval
HoldTime in both this tables are different.

For example, i have two query:
select sum(HoldTime) as HoldTime
from icm0_hds.dbo.Agent_Skill_Group_Interval (nolock)
where DateTime between '2021-03-01' and '2021-03-02' and SkillGroupSkillTargetID = 8826

Value - 297586

select sum(HoldTime) as HoldTime
from icm0_hds.dbo.Agent_Skill_Group_Interval (nolock)
where DateTime between '2021-03-01' and '2021-03-02' and SkillGroupSkillTargetID = 8826

Value - 308068

From DB scheme it's not clear how it is counts.

Can someone explain how it works?

[TalkingScientist]

Can you try these 2 queries and see if it gives more insight? 

SELECT
  SUM(HoldTime) AS HoldTime,
  SUM(IncomingCallsOnHoldTime) AS IncomingCallsOnHoldTime,
  SUM(InternalCallsOnHoldTime) AS InternalCallsOnHoldTime,
  SUM(PreviewCallsOnHoldTime) AS PreviewCallsOnHoldTime,
  SUM(ReserveCallsOnHoldTime) AS ReserveCallsOnHoldTime
FROM icm0_hds.dbo.Agent_Skill_Group_Interval (NOLOCK)
WHERE
  DateTime BETWEEN '2021-03-01' AND '2021-03-02'
  AND SkillGroupSkillTargetID = 8826

SELECT
  SUM(HoldTime) AS HoldTime
FROM icm0_hds.dbo.Call_Type_SG_Interval (NOLOCK)
WHERE
  DateTime BETWEEN '2021-03-01' AND '2021-03-02'
  AND SkillGroupSkillTargetID = 8826

[Malen]

Hello, @TalkingScientist

Made your query and the value is the same.
But i don't understand difference between HoldTime and IncomingCallsOnHoldTime.
Can you explain it?

[TalkingScientist]

Well, I thought I could. 
I 'thought' HoldTime was an aggregate of Incoming, Internal, Predictive Outbound. 

Then you posted that screenshot and HoldTime is less than IncomingCallsOnHoldTime, now I'm questioning the existence of reality and frankly it's starting my day off sour.