[Django] #28888: Index added to _meta.indexes with Meta.indexes=[] yields two equal addIndex() operations.
Django
addIndex() operations.
--------------------------------------------------+------------------------
Reporter: Jan Pieter Waagmeester | Owner: nobody
Type: Uncategorized | Status: new
Component: Migrations | Version: 1.11
Severity: Normal | Keywords:
Triage Stage: Unreviewed | Has patch: 0
Needs documentation: 0 | Needs tests: 0
Patch needs improvement: 0 | Easy pickings: 0
UI/UX: 0 |
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I use a custom field derived from
`django.contrib.postgres.fields.JSONField`, which adds an `GinIndex` to
`model._meta.indexes`:
{{{
from django.contrib.postgres.fields import JSONField
from django.contrib.postgres.indexes import GinIndex
class CustomJSONField(JSONField):
def contribute_to_class(self, cls, name):
super(CustomJSONField, self).contribute_to_class(cls, name)
index = GinIndex(fields=[name])
index.set_name_with_model(cls)
cls._meta.indexes.append(index)
}}}
When used in a model like this,
{{{
class Blog(models.Model):
title = models.CharField(max_length=100)
json = CustomJSONField()
}}}
Migrations for model and index are created as expected:
{{{
./manage.py --version
1.11.8
./manage.py makemigrations app
Migrations for 'app':
app/migrations/0001_initial.py
- Create model Blog
- Create index app_blog_json_2cf556_gin on field(s) json of model blog
}}}
But when I add an empty list of indexes like this:
{{{
class Blog(models.Model):
title = models.CharField(max_length=100)
json = CustomJSONField()
class Meta:
indexes = []
}}}
two indexes are created:
{{{
rm -rf app/migrations
./manage.py --version
1.11.8
./manage.py makemigrations app
Migrations for 'app':
app/migrations/0001_initial.py
- Create model Blog
- Create index app_blog_json_2cf556_gin on field(s) json of model blog
- Create index app_blog_json_2cf556_gin on field(s) json of model blog
}}}
Which of course results in `django.db.utils.ProgrammingError: relation
"app_blog_json_2cf556_gin" already exists`.
--
Ticket URL: <https://code.djangoproject.com/ticket/28888>
Django <https://code.djangoproject.com/>
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Django
addIndex() operations.
Reporter: Jan Pieter | Owner: nobody
Waagmeester |
Type: Uncategorized | Status: new
Component: Migrations | Version: 1.11
Keywords: | Triage Stage:
| Unreviewed
Has patch: 0 | Needs documentation: 0
Needs tests: 0 | Patch needs improvement: 0
Easy pickings: 0 | UI/UX: 0
Description changed by Jan Pieter Waagmeester:
Old description:
New description:
I use a custom field derived from
`django.contrib.postgres.fields.JSONField`, which adds an `GinIndex` to
`model._meta.indexes`:
{{{
from django.contrib.postgres.fields import JSONField
from django.contrib.postgres.indexes import GinIndex
class CustomJSONField(JSONField):
def contribute_to_class(self, cls, name):
super(CustomJSONField, self).contribute_to_class(cls, name)
index = GinIndex(fields=[name])
index.set_name_with_model(cls)
cls._meta.indexes.append(index)
}}}
When used in a model like this,
{{{
class Blog(models.Model):
title = models.CharField(max_length=100)
json = CustomJSONField()
}}}
Migrations for model and index are created as expected:
{{{
./manage.py --version
1.11.8
./manage.py makemigrations app
Migrations for 'app':
app/migrations/0001_initial.py
- Create model Blog
- Create index app_blog_json_2cf556_gin on field(s) json of model blog
}}}
But when I add an empty list of indexes to `class Meta` like this:
{{{
class Blog(models.Model):
title = models.CharField(max_length=100)
json = CustomJSONField()
class Meta:
indexes = []
}}}
two indexes are created:
{{{
rm -rf app/migrations
./manage.py --version
1.11.8
./manage.py makemigrations app
Migrations for 'app':
app/migrations/0001_initial.py
- Create model Blog
- Create index app_blog_json_2cf556_gin on field(s) json of model blog
- Create index app_blog_json_2cf556_gin on field(s) json of model blog
}}}
Which of course results in `django.db.utils.ProgrammingError: relation
"app_blog_json_2cf556_gin" already exists`.
--
--
Ticket URL: <https://code.djangoproject.com/ticket/28888#comment:1>
Django
addIndex() operations.
Reporter: Jan Pieter | Owner: nobody
Waagmeester |
Component: Migrations | Version: 1.11
Keywords: | Triage Stage:
| Unreviewed
Has patch: 0 | Needs documentation: 0
Needs tests: 0 | Patch needs improvement: 0
Easy pickings: 0 | UI/UX: 0
Comment (by Jan Pieter Waagmeester):
Possibly unrelated, but:
When an initial migration is added without the index added to
`cls._meta.indexes`, resulting in the output
{{{
./manage.py makemigrations app
Migrations for 'app':
app/migrations/0001_initial.py
- Create model Blog
}}}
No index is added, as expected.
However, adding the index to `cls._meta.indexes` has no effect: `No
changes detected in app 'app'`.
--
Ticket URL: <https://code.djangoproject.com/ticket/28888#comment:2>
Django
addIndex() operations.
Reporter: Jan Pieter | Owner: nobody
Waagmeester |
Component: Migrations | Version: 1.11
Keywords: | Triage Stage:
| Unreviewed
Has patch: 0 | Needs documentation: 0
Needs tests: 0 | Patch needs improvement: 0
Easy pickings: 0 | UI/UX: 0
Comment (by Tim Graham):
As there's no documented support for adding indexes in
`Field.contribute_to_class()`, can you explain why Django is at fault
and/or propose a patch?
--
Ticket URL: <https://code.djangoproject.com/ticket/28888#comment:3>
Django
addIndex() operations.
Reporter: Jan Pieter | Owner: nobody
Waagmeester |
Component: Migrations | Version: 1.11
Keywords: | Triage Stage:
| Unreviewed
Has patch: 0 | Needs documentation: 0
Needs tests: 0 | Patch needs improvement: 0
Easy pickings: 0 | UI/UX: 0
Comment (by Jan Pieter Waagmeester):
I understand that "there's no documented support for adding indexes in
`Field.contribute_to_class()`" and I'm open to suggestions to other
solutions to add indexes with a field.
But this seems the cleanest way to do it, and support seems to be almost
there/halfway there. I'm willing to invest time to create a patch to fix
this, but I'd like to have some degree of confidence that such a solution
would be desirable functionality.
--
Ticket URL: <https://code.djangoproject.com/ticket/28888#comment:4>
Django
addIndex() operations.
Reporter: Jan Pieter | Owner: nobody
Waagmeester |
Cleanup/optimization |
Component: Database layer | Version: 1.11
(models, ORM) |
Severity: Normal | Resolution:
Keywords: | Triage Stage:
Has patch: 0 | Needs documentation: 0
Needs tests: 0 | Patch needs improvement: 0
Easy pickings: 0 | UI/UX: 0
Changes (by Tim Graham):
* component: Migrations => Database layer (models, ORM)
* type: Uncategorized => Cleanup/optimization
* stage: Unreviewed => Someday/Maybe
Comment:
Usually it's more effective to use the DevelopersMailingList to get
feedback and consensus on design decisions as it reaches a wider audience
than the ticket tracker.
--
Ticket URL: <https://code.djangoproject.com/ticket/28888#comment:5>