>>Performance wise I know we should avoid having scalar functions on the left side of the equal in the where clause. Anybody have an idea on how to avoid it in something like below?
>>
>>Thanks
>>
>>

>>Select min(sdatetime) as FirstDate 
>>from dbo.Meetings (nolock) 
>>where iscancelled=0
>>and roomclosed=0
>>and isblock=0
>>and substring(scheduledBy,1,4)<>'TEST'
>>and substring(scheduledBy,1,3)<>'CQI'
>>

>
>
>There may be other ways
>
>

>>Select min(sdatetime) as FirstDate 
>>from dbo.Meetings (nolock) 
>>where iscancelled=0
>>and roomclosed=0
>>and isblock=0
>and scheduledBy not like 'TEST%'  
>and scheduledBy not like 'CQI%'
>

The other way would be a left join with itself and a like condition, e.g.

;with cte_ToExclude as (select IDField 
from dbo.Meetings (nolock) 
where iscancelled=0
and roomclosed=0
and isblock=0
and (scheduledBy like 'TEST%'  
OR scheduledBy like 'CQI%'))

select min(M.sDateTime) as FirstDate 
from dbo.Meetings (nolock) M
where M.iscancelled=0
and M.roomclosed=0
and M.isblock=0 LEFT JOIN cte_ToExclude C on M.IdField = C.IDField where c.IDField IS NULL

Or use not exist condition here:

select min(M.sDateTime) as FirstDatefrom dbo.Meetings (nolock) M
where M.iscancelled=0
and M.roomclosed=0
and not exists(select 1 from 
from dbo.Meetings (nolock)  M2
where M2.iscancelled=0
and M2.roomclosed=0
and M2.isblock=0
and M2.scheduledBy like 'TEST%'  and M2.IdField = M1.IDField) and not exists (select 1 from 
from dbo.Meetings (nolock)  M3
where M3.iscancelled=0
and M3.roomclosed=0
and M3.isblock=0
and M3.scheduledBy like 'CQl%'  and M3.IdField = M1.IDField)