Clarity

Please advise why CA PPM only support Microsoft SQL enterprise edition but not standard edition? If only enterprise edition supported, for non production environment ie development or test environment can we use Microsoft SQL developer edition? Else the entire setup cost is very expensive. Thank you

IIRC* its because of the way that the different SQL versions optimised some queries - under standard this caused performance problems. 

If your non-production environments are on unsupported stacks then it's your problem when something goes wrong / you identify a bug - if you can live with that risk (and you can get it to run on unsupported stacks) then in my opinion that is up to you - but you should expect no support/help from CA when trying to get it running or when you have any problems with it (problems would need to be recreated on a supported stack if you require support).

(I don't work for CA so take that advice as advice not anything formal, you would need to talk to your account representative for that)

EDIT: * - what I'm remembering was based on discussions like this one ; SQL Server 2008 R2 - STANDARD Edition - Acceptable/Impact? 

It's a quirky feature that for some reason MS only includes in the Enterprise edition.  It has to do with how the optimizer deals with indexed views.  The standard edition supports indexed views but the query optimizer (under the hood) doesn't take them into account. 

CA PPM most commonly uses this in the security views.  These views can get called dozens of times on a page.  If the differ in performance of the the call is 5ms to 50ms (just as example; it can be vary more or less), then the tools feels slow and sluggish.

-Josh