I think I agree with Markus that we do not yet have a good enough performance story to make migrations mandatory. If you want to ditch them and do your own database management, we should let you - which we could do with some kind of MIGRATIONS_MODULES opt-out that basically sets everything to pseudo-unmanaged, but I see no reason not to have the syncdb-like solution keep working as it at least runs off of SchemaEditor now.
Andrew On Thu, Aug 27, 2015 at 5:14 PM, Markus Holtermann <[email protected] > wrote: > The general benefit of *not* having migrations is the incredible better > performance to setup the tables. Especially for larger projects this is > something we should at least keep in mind (see > https://code.djangoproject.com/ticket/24743). I spent a fair bit of time > on the issue and have not yet found a satisfying solution. > > Supporting apps without migrations would essentially continue to support > the old `syncdb` behavior, though not as a standalone command, but as a > flag for `manage.py migrate`. It takes the models from those apps and calls > `schema_editor.create_model()`, taking the deferred SQL and running it > after all models of apps w/o migrations have been created (current behavior > [in tests] I think). This would continue to raise issues if models in apps > w/o migrations refer to models in apps w/ migrations (missing constraints), > but that is a limitation we had since 1.7 (silent failure; 1.8 fails loud). > > While migrations should provide *the* way to maintain your database I see > the points that have been made in other recent discussions. Although Django > doesn't force you to use migrations there are some things (e.g. not create > the `django_migrations` table) we probably should not do unless you > actually use migrations. > > We might want to consider looking at the `MIGRATION_MODULES` settings > variable and allowing to set values to `None` in order to disable > migrations for that app, but that's a different story. > > /Markus > > > On Friday, August 28, 2015 at 4:26:19 AM UTC+10, Tim Graham wrote: >> >> It would be great if we could decide this by next Friday (September 4) or >> so, so that we have some time to do the necessary implementations and >> testing before alpha. (For example, running manage.py test without >> migrations currently gives "no such table ...". It would be nice to give a >> friendlier message if we require migrations for running tests >> (https://github.com/django/django/pull/5100 does this to some extent, >> but could be improved I think). >> >> I know at least Markus said he would like to present an argument for >> keeping support for apps without migrations. >> >> On Thursday, August 13, 2015 at 1:56:05 PM UTC-4, Tim Graham wrote: >>> >>> It's a one line change in the code to keep the status quo from 1.8. The >>> main drawback I see is continued support tickets about dependencies between >>> apps with and without migrations. I already removed the documentation >>> describing the problem and "won't fixed" tickets that suggested doing more >>> to detect and throw errors about these cases. >>> >>> I guess I'd like here why migrations could be a hindrance "for quick >>> prototyping and initial development." I'd argue that starting with >>> migrations from the start (manage.py makemigrations && manage.py migrate) >>> will save the need to learn about --fake-initial if you decide to add >>> migrations at some point later (and of course avoid dependency issues). Is >>> "manage.py makemigrations && manage.py migrate" more difficult that the >>> proposed ""manage.py migrate --allow-apps-without-migrations"? Am I missing >>> a motive behind the request? >>> >>> diff --git a/django/core/management/commands/migrate.py >>> b/django/core/management >>> index 2f04824..dec86e1 100644 >>> --- a/django/core/management/commands/migrate.py >>> +++ b/django/core/management/commands/migrate.py >>> @@ -133,7 +133,7 @@ class Command(BaseCommand): >>> targets = executor.loader.graph.leaf_nodes() >>> >>> plan = executor.migration_plan(targets) >>> - run_syncdb = options.get('run_syncdb') and >>> executor.loader.unmigrated_a >>> + run_syncdb = bool(executor.loader.unmigrated_apps) >>> >>> # Print some useful info >>> if self.verbosity >= 1: >>> >>> On Thursday, August 6, 2015 at 9:50:10 PM UTC-4, Markus Holtermann wrote: >>>> >>>> Instead of rushing to a decision if and of how we continue to support >>>> "apps w/o migrations" I would argue that, since Django's test suite >>>> does >>>> infact create tables for apps w/o migrations, we could add a >>>> commandline >>>> flag (e.g. --run-syncdb or whatever) to the migrate command and warn >>>> the >>>> user if there are apps w/o migrations an the user doesn't supplied: >>>> >>>> https://github.com/django/django/blob/master/django/core/management/commands/migrate.py#L136 >>>> >>>> /Markus >>>> >>>> On Thu, Aug 06, 2015 at 05:26:50PM -0700, Andrew Godwin wrote: >>>> >Do we know exactly what "support for apps without migrations" would >>>> consist >>>> >of at this point? I have that half-done code for replicating syncdb >>>> with >>>> >the autodetector stuck onto the migration executor, but it's not >>>> especially >>>> >speedy and would need some work to make it a sensible speed before it >>>> goes >>>> >forward. >>>> > >>>> >Alternately, we could modify the autodetector to have a "create only" >>>> mode >>>> >that's more efficient or just write a new generator that is quick >>>> because >>>> >it knows it's only making nonmigrated apps' migrations. >>>> > >>>> >Andrew >>>> > >>>> >On Thu, Aug 6, 2015 at 4:56 PM, Tim Graham <[email protected]> >>>> wrote: >>>> > >>>> >> With the alpha for 1.9 coming up in 6 weeks, we need to decide >>>> whether or >>>> >> not to continue support for apps without migrations (currently in >>>> master no >>>> >> tables are created for such apps (as the deprecation timeline says), >>>> but it >>>> >> might be appropriate to add a warning or error message for this case >>>> if >>>> >> things don't change). >>>> >> >>>> >> Is anyone sufficiently interested in continuing support for apps >>>> without >>>> >> migrations to commit to completing it by the alpha? If not, do you >>>> consider >>>> >> it a release blocker that I should spend time on? >>>> >> >>>> >> Related tickets: >>>> >> >>>> >> https://code.djangoproject.com/ticket/25144 - No way to create >>>> tables for >>>> >> apps without migrations >>>> >> https://code.djangoproject.com/ticket/24919 - Add an option not to >>>> run >>>> >> migrations when running tests >>>> >> https://code.djangoproject.com/ticket/24481 - Improve sqlmigrate to >>>> be >>>> >> more flexible and allow bypassing migrations on disk >>>> >> https://code.djangoproject.com/ticket/24901 - makemigrations should >>>> >> create empty migrations dir for any installed app without it >>>> >> https://code.djangoproject.com/ticket/24588 - Improve handling apps >>>> >> without migrations while running migrate command. >>>> >> >>>> >> On Sunday, January 18, 2015 at 5:11:53 PM UTC-5, Markus Holtermann >>>> wrote: >>>> >>> >>>> >>> Creating in-memory migrations for all apps that don't have >>>> migration >>>> >>> files seems to be an option to solve the dependency problem. This >>>> would >>>> >>> even allow apps without migrations to depend on those with >>>> migrations. >>>> >>> >>>> >>> We have to consider though, that there are tens of apps and >>>> hundreds of >>>> >>> models in our own test suite, and generating all migrations during >>>> start >>>> >>> seems to be quite an expensive task. And I'm not even talking about >>>> the >>>> >>> migration optimizer which probably needs to get a lot smarter if we >>>> take >>>> >>> this road. >>>> >>> >>>> >>> syncdb, which leaves a developer with a database scheme that cannot >>>> be >>>> >>> altered automatically, is something we should get rid of as soon as >>>> >>> possible, especially since Django has a out-of-the-box migration >>>> system. >>>> >>> >>>> >>> /Markus >>>> >>> >>>> >>> On Sun, Jan 18, 2015 at 01:50:14PM -0800, Andrew Godwin wrote: >>>> >>> >My main argument for removing them entirely was the dependency >>>> issues >>>> >>> >between apps with and without migrations. Having syncdb use >>>> SchemaEditor >>>> >>> is >>>> >>> >a big step and one I'm happy we've got to, but the only advantage >>>> of >>>> >>> >keeping syncdb is for the test suite and I'd rather we approach >>>> that >>>> >>> more >>>> >>> >as "migrations made and run at runtime as a special case" rather >>>> than >>>> >>> >"syncdb". >>>> >>> > >>>> >>> >If nothing else, I'd like to see the end-developer-facing parts, >>>> like >>>> >>> the >>>> >>> >syncdb command itself, gone. >>>> >>> > >>>> >>> >Andrew >>>> >>> > >>>> >>> >On Sun, Jan 18, 2015 at 1:43 PM, Claude Paroz <[email protected]> >>>> >>>> >>> wrote: >>>> >>> > >>>> >>> >> Tim recently did a fabulous job of removing deprecated code for >>>> the >>>> >>> >> future 1.9 on master. Thanks for that. >>>> >>> >> >>>> >>> >> However, one thing he removed was support for apps without >>>> migrations. >>>> >>> >> >>>> >>> >> >>>> >>> >>>> https://github.com/django/django/commit/7e8cf74dc74539f40f4cea53c1e8bba82791fcb6 >>>> >>> >> >>>> >>> >> Considering that we have to keep internal support for Django's >>>> own >>>> >>> test >>>> >>> >> suite anyway, I wonder if we should remove that support at all >>>> for >>>> >>> >> "normal" projects. I think one of Andrew's motivation was not to >>>> have >>>> >>> to >>>> >>> >> keep two schema editing code bases. But now that the old syncdb >>>> also >>>> >>> >> uses the new schema editor, I think that this argument doesn't >>>> stand. >>>> >>> >> >>>> >>> >> So what about keeping support for apps without migrations in the >>>> >>> longer >>>> >>> >> term. Of course, the fact that those apps cannot depend on >>>> migrated >>>> >>> apps >>>> >>> >> limits its use, but I think that for quick prototyping and >>>> initial >>>> >>> >> developement, migrations could be more of a hindrance. Would you >>>> see >>>> >>> >> major drawbacks with keeping this support? >>>> >>> >> >>>> >>> >> Opinions welcome. >>>> >>> >> >>>> >>> >> Claude >>>> >>> >> -- >>>> >>> >> www.2xlibre.net >>>> >>> >>>> >> -- >>>> >> You received this message because you are subscribed to the Google >>>> Groups >>>> >> "Django developers (Contributions to Django itself)" group. >>>> >> To unsubscribe from this group and stop receiving emails from it, >>>> send an >>>> >> email to [email protected]. >>>> >> To post to this group, send email to [email protected]. >>>> >> Visit this group at http://groups.google.com/group/django-developers. >>>> >>>> >> To view this discussion on the web visit >>>> >> >>>> https://groups.google.com/d/msgid/django-developers/89839628-6b11-4c61-86ed-4d9a076e9e3d%40googlegroups.com >>>> >> < >>>> https://groups.google.com/d/msgid/django-developers/89839628-6b11-4c61-86ed-4d9a076e9e3d%40googlegroups.com?utm_medium=email&utm_source=footer> >>>> >>>> >> . >>>> >> >>>> >> For more options, visit https://groups.google.com/d/optout. >>>> >> >>>> > >>>> >-- >>>> >You received this message because you are subscribed to the Google >>>> Groups "Django developers (Contributions to Django itself)" group. >>>> >To unsubscribe from this group and stop receiving emails from it, send >>>> an email to [email protected]. >>>> >To post to this group, send email to [email protected]. >>>> >Visit this group at http://groups.google.com/group/django-developers. >>>> >To view this discussion on the web visit >>>> https://groups.google.com/d/msgid/django-developers/CAFwN1urojSqXkaDnjVdrPHrs5TKpQC-baz9TZLtvOZ_3UJ%2BM2Q%40mail.gmail.com. >>>> >>>> >For more options, visit https://groups.google.com/d/optout. >>>> >>>> -- >>>> >>> -- > You received this message because you are subscribed to the Google Groups > "Django developers (Contributions to Django itself)" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to [email protected]. > To post to this group, send email to [email protected]. > Visit this group at http://groups.google.com/group/django-developers. > To view this discussion on the web visit > https://groups.google.com/d/msgid/django-developers/b079f398-92fb-43e4-8ab5-6c1c8dbc9b09%40googlegroups.com > <https://groups.google.com/d/msgid/django-developers/b079f398-92fb-43e4-8ab5-6c1c8dbc9b09%40googlegroups.com?utm_medium=email&utm_source=footer> > . > > For more options, visit https://groups.google.com/d/optout. > -- You received this message because you are subscribed to the Google Groups "Django developers (Contributions to Django itself)" group. 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