How do reports work?

[Me]

I have a report that runs into a few pages, when I do print preview, it shows
me the output, but it continues to show me 'Querying ...' on display bar. Why
does it show that?

Isn't it supposed to run the entire report, keep results in buffer and then
show it on screen?

Or something is wrong with my query(for report) and I need to take a look at
it?

Thank you,
-Me

 

[Allen Browne]

There are so many variables here that could affect how Access works.

Does the query contain calculated fields? If so, Access may calculate those
fields only when the records are called for. Same thing can occur if the
controls on the report have expressions in their Control Source.

The report may also perform sorting and/or grouping of results, which can
trigger further calculations and retrievals.

Conditional formatting of the controls can also trigger further calcuations.

Any code in the events of the report's sections can too.

The properties of the sections can also cause lots of calculations to take
place as Access plots a solution. This is more involved if the sections have
the Can Grow or Can Shrink properites set, if they use Keep Together, or
Force New Page, or if you code changes the runtime properties of the report
such as PrintSection, MoveLayout, NextRecord.

Then there's the aggregation (totals, averages, ...) than can occur in
section footers, and so on.

In short, there's a lot of stuff for Access to calculate.