Large Union Queries

  • Thread starter Thread starter Nathan
  • Start date Start date
N

Nathan

Hi,

I have a large union query that adds together a number of
different tables and appends them to a one table. Most
of the queries have a group by in them to summarize the
data by month. What I was wondering it is more efficient
to place a where clause limiting the dates, or in each
component of the union?

Mark
 
Probably more efficient to have a where clause limiting the result by date range
within each component of the UNION query.

BUT, how big are your tables going to be and how much time will you really save?
 
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