The answer is to not use a temp table at all. This query can be written AND run much more efficiently by using what is referred to as a virtual table. It looks something like this:
Select col1, sum(col2) testsum Into #temp >From table1 Group by col1 Select col1, col4, sum(testsum) secondaryagg >From table2 inner join #temp on table2.col1 = #temp.col1 Group by col1, col4VIRTUAL TABLE:
Select col1, col4, sum(testsum) secondaryagg >From table2 inner join (Select col1, sum(col2) testsum From table1 Group by col1) a on table2.col1 = a.col1 Group by col1, col4
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This was first published in September 2003