Question

I’m using this code to replicate Data Driven Subscriptions in MSSQL 2008.

http://sqlblog.com/blogs/greg_low/archive/2008/08/13/data-driven-subscriptions-in-sql-server-2005-standard-edition.aspx

As part of the queueing system it uses a

WAITFOR DELAY '00:00:30';

I’m planning on using this for over 200+ reports.

Will I have to schedule them to run at different times or will it all happily run queueing the reports and what is the performance hit?

Thanks

Answer 1

First, there is essentially no perormance hit (to other queries using) waitfor – its what it is amongst other things designed ie – releasing the processor to do other things. The question is what else is scheduled for then – Backups etc? I would be inclined to test the time taken for each report and write to a table (for your 201+ th report). It really depends on how intensive your reports are – and the fact that you are scheduling them for a quiet time suggests your resources are not limitless. I would be inclined to schedule reports for different time – even if only 5 seconds apart – specially if preceeding the report takes between 1 and 4 seconds. The sql batch will then be slightly more complex but run more smoothly. Also a query which tells you when reports have overlapped can help your scheduling. If you have parallelismn turned off and have 4 processors, you may run 4 reports at a time, but check your disk queue as well.