[Clas12_calcom] database tables

[Mac Mestayer]

Cole;

We absolutely have to be able to control variations of other
detector's configurations.  I agree on that.

So let's say we want to understand the effect of geometry
misalignments.  So we say, "runs 120-160 will be devoted to
alignment studies".  How is that easier than saying "variations
named "alignment studies" will be devoted to alignment studies"?

An appropriate use of run numbers is to study run-dependent
changes to gemc, for example.  So maybe Mauri generates events
at five different values of luminosity and gives them run numbers
121 - 125.  That's fine.  Then you do your luminosity studies
while changing your cluster-finding algorithms using your variation
names "little cluster", "medium cluster" and "big cluster" for the
calorimeters.  And say you want to keep the DC's constant.
So you use the DC calibrations "nominal" with a fixed time-stamp.
Then you do your studies and see how your efficiency changes with
luminosity.  I would argue that you don't want me or the DC group
to know anything about those run numbers because it gets really
confusing if we start putting in run-number dependent constants.

 				- Mac

"mestayer at jlab.org", (757)-269-7252

On Fri, 1 Apr 2016, Cole Smith wrote:

>
> Mac,
>
> The discussion about how to use run ranges in MC studies mainly
> arose to avoid complicated naming schemes for variations.  This
> was noted as a potential problem in the original CCDB specification
> document by Mark.  Some of us want to do sector only or layer only
> variations for calibration systematics studies and may want to exclude
> other detector variations that introduce unwanted variations. Somehow
> it has to be made easy to know whose variation does what. So either
> we impose some naming convention for variations or restrict run ranges
> to specific combinations.
>
> That said, I like the suggestion that run ranges denote broad study
> categories like luminosity, geometry configurations, KPP or calibration.
> Perhaps that is a better way to preserve some order and avoid variation
> proliferation.
>
> Cole
>
> On Fri, 1 Apr 2016, Mac Mestayer wrote:
>
>> Dear CALCOM group;
>> 
>> Thanks for the concise and well-written guidelines.
>> They are very good for focussing discussion.
>> 
>> I agree with most of the 'best practices' advocated, so
>> I will only mention my two disagreements here:
>> 
>> 1) sector, layer, component need not be enforced on the
>> tables (CCDB is much more flexible than CALDB was in this regard).
>> Not only that, but sector, layer, component is not at all applicable
>> to the drift chamber data-base.  See 
>> https://clasweb.jlab.org/wiki/index.php/DC-calibration_Constants
>> for a description of the DC calibration table structure.
>> We use indices like region, superlayer or region, superlayer, board, 
>> connector, etc. and I refuse to call a superlayer a layer, etc.
>> There is no need to try to enforce a false structure on everyone.
>> 
>> 2) we should not use run number to denote a variation, such as
>> Monte Carlo.  This is precisely what variations are designed to do.
>> Talk to Hall D to find out how they use various variations to denote
>> Monte Carlo.  In fact, I think we may want to use actual run number
>> ranges for the Monte Carlo variations to follow, for example, different
>> luminosities and this proposed use of run numbers will just confuse
>> people.
>>
>> 				regards, Mac
>> 
>> "mestayer at jlab.org", (757)-269-7252
>> 
>> On Fri, 1 Apr 2016, Raffaella De Vita wrote:
>>
>>>  Dear Harut and Bryan,
>>>  following the discussion we had on the database, we have collected a set
>>>  of "guidelines" concerning the calibration constants table structure, the
>>>  use of variations, the use of run numbers etc.  that we would like to
>>>  distribute. You can find in attachment the document we have produced.
>>>  Let us know what you think about it.
>>>  Best regards,
>>>     Raffaella
>>> 
>>> 
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>> 
>