the single precise purpose of isnumeric when used on strings is to determine whether the string conforms to TSQL rules for specifying numeric literals. That is not the same as consisting...

that will only work once a year, at the end of june, won't it?

you would also need to remove the trailing comma from the string if you use the above approach.

If your circumstances permit, you should separate the "product line name", as I will call it:

substring

(prodid,1,len(prodid)-(sign(

select

dateadd(hour,4,dateadd(d,0,datediff(d

is that using indexed calc columns?

Have you used a text-comparison tool like textpad to check for differences in the detail of the execution plans?

Use the SQL Server-specific counters. Perfmon is mostly meant for broad-brush analysis of performance as a whole. If you can get exclusive access to SQL Server on both servers while...

You'll need to post code to get more specific suggestions.

Try looking at perfmon counters on the servers (if you can get a quiet time to do it on the prod server) to check which resource is affected.

Other than that,...

--equivalently,

select distinct top 10 so.*

from sysobjects so

inner join [dbo].[Test_table] t

on so.name = t.fileformat

--or if fileformat has low cardinality relative to table height,

--possibly:

Tim Wilkinson

"If it doesn't work in practice, you're using the wrong theory"
- Immanuel Kant