[bug#32879] [PATCH] database: Add builds only if one of their outputs is new.

[Ludovic Courtès]

Hello!

Clément Lassieur <address@hidden> skribis:

> Clément Lassieur <address@hidden> writes:
>
>> Ludovic Courtès <address@hidden> writes:
>>
>>> Hello Clément,
>>>
>>> Clément Lassieur <address@hidden> skribis:
>>>
>>>> * Makefile.am (dist_sql_DATA): Add 'src/sql/upgrade-4.sql'.
>>>> * src/cuirass/database.scm (db-add-output): New procedure.
>>>> (db-add-build): Call DB-ADD-OUTPUT, rollback the transaction and return #f 
>>>> if
>>>> DB-ADD-OUTPUT returned an empty list.
>>>> * src/schema.sql (Outputs): Set 'path' as primary key, instead of 
>>>> 'derivation,
>>>> name'.
>>>> * src/sql/upgrade-4.sql: New file with SQL queries to upgrade the database.
>>>> * tests/database.scm (make-dummy-build): Use the #:OUTPUTS key.  Get 
>>>> default
>>>> OUTPUTS to depend on DRV.
>>>> ("db-add-build-with-fixed-output"): New test.
>>>
>>> What’s the rationale?  I suppose having a simpler primary key for
>>> ‘Outputs’ might help performance?
>>
>> There is a slight performance and db size gain but the primary reason is
>> to have a better idea of Cuirass' load when looking at the pending
>> builds.  There will be less (no?) 'fake' builds.  The idea is that all
>> builds should be real builds.
>
> Also, it would allow to be notified when someone pushes on master a
> commit that triggers too many builds.

That makes a lot of sense, thank you!

IMO you can go ahead and push it.

Ludo’.