I am trying to concatenate LoadIds for a user using For XML path which is a portion of my whole query, I verified that the maximum time gets elapsed in calculating this concatenated LoadId column. Below is the syntax, can anyone suggest a way to rewrite this efficiently?
LoadIds = STUFF((SELECT ' , ' + CAST([LoadId] AS varchar(5))
FROM Table1 AS t1
WHERE t1.[UserId] = [t2].[UserId]
FOR XML PATH ('')), 1, 2, '')
Table1 AS t2