Multiple subreports to run off the same selected data

[pvirsf]

Is it true that subreports run independently and independently retrieve data from the data source per the tables, links, and selection defined in the subreport?

I am running CR 9 on a MS SQL Server db.
I want to have 4 subreports with different grouping and totaling schemes, run from a primary report and they would ordinarily run on identical sets of data.

I am wondering if performance would be improved if a single common selection of data could be done in the primary report for subsequent individual grouping, totaling, etc by each of the 4 subreports? Any thoughts out there?

 

[rac2]

Your question seems more appropriate for the Crystal Reports forum. Reports and subreports are not part of SQL or SQL Server.

As to the SQL Server performance, it is so fast that it really doesnt matter whether you SELECT and GROUP BY four times or prepare a temporary table with one SELECT then do the four GROUP BY queries on the smaller dataset. The SELECT would have to be extraordinarily complex and involve an enourmous number of rows from an incredibly poorly designed database before the latter approach would offer any advantage.