Often a DSUM can be replaced by creating another Totals query that
calculates the value that needs to be summed, then joining it to your
main query.

The totals query will calculate the Sum values all at once, which is
usually much more efficient than DSUMs.

Armen Stein
Microsoft Access MVP
www.JStreetTech.com

There may be other things that can also help with performance in a
multi user environment.   Mind you removing DSUMs would be very high
on my list too.

The three most common performance problems in Access 2000 or newer
are:
 - LDB locking which a persistent recordset connection or an always
open bound form corrects (multiple users)
 - sub datasheet Name property set to [Auto] should be [None]
 - Track name AutoCorrect should be off

For more information on these, less likely causes, other tips and
links to MS KB articles visit my Access Performance FAQ page at
http://www.granite.ab.ca/access/performancefaq.htm

I specifically created the Auto FE Updater utility so that I could
make changes to the FE MDE as often as I wanted and be quite confident
that the next time someone went to run the app that it would pull in
the latest version.  For more info on the errors or the Auto FE
Updater utility see the free Auto FE Updater utility at
http://www.granite.ab.ca/access/autofe.htm at my website to keep the
FE on each PC up to date.

Tony

A DSUM sums the values across a bunch of records.  If you have
10 records, it is 10 times slower than if you have 1 record.

That has nothing to do with if DSUM is slow: it is just the design
of your query.

So the first thing is always to think about how many records you
are summing, and how often you are doing it.

Sometimes it is even better to make a temporary table and put all
your sums in that, so that you don't have to do it again and again.

Sums in the criteria section are particularly bad: sums that have
record-based criteria are even worse (much worse). That is,
sums like DSUM("field","table","fld_2 =" + [fld_3)

Sometimes it is worthwhile to replace all the DSUM with your own
DSUM function, like this: http://mvps.org/access/modules/mdl0012.htm
(This makes less difference now than it did when it was written)