#27996: Add pgcrypto extension and GEN_RANDOM_UUID function to contrib.postgres
-------------------------------------+-------------------------------------
Reporter: Paolo | Owner: Paolo Melchiorre
Melchiorre |
Type: New | Status: assigned
feature |
Component: | Version: master
contrib.postgres | Keywords: uuid extension
Severity: Normal | function random postgresql
Triage Stage: | cryptography
Unreviewed | Has patch: 1
Needs documentation: 0 | Needs tests: 0
Patch needs improvement: 0 | Easy pickings: 0
UI/UX: 0 |
-------------------------------------+-------------------------------------
After the introduction of the UUID Field in Django 1.8, I believe that
django.contrib.postgres could benefit from some custom functions based on
the pgcrypto extension of PostgreSQL (see
https://www.postgresql.org/docs/9.6/static/pgcrypto.html). That kind of
functions would be very helpful for apply a migration that adds a unique
non-nullable field to a table with existing rows.
Starting from "Migrations that add unique fields" (see
https://docs.djangoproject.com/en/dev/howto/writing-migrations
/#migrations-that-add-unique-fields) I speed up the `gen_uuid` using
`GEN_RANDOM_UUID` function, I change the function from:
{{{
import uuid
def gen_uuid(apps, schema_editor):
MyModel = apps.get_model('myapp', 'MyModel')
for row in MyModel.objects.all():
row.uuid = uuid.uuid4()
row.save(update_fields=['uuid'])
}}}
to
{{{
from django.contrib.postgres.functions import RandomUUID
def gen_uuid(apps, schema_editor):
MyModel = apps.get_model('myapp', 'MyModel')
MyModel.objects.update(uuid=RandomUUID())
}}}
Using this function on my system the time to migrate more than 10000
objects decreased from
{{{
real 0m15.988s
user 0m10.680s
sys 0m0.508s
}}}
to
{{{
real 0m2.957s
user 0m1.736s
sys 0m0.072s
}}}
I already implemented a solution for thi feature and I'm crating a related
pull request.
--
Ticket URL: <https://code.djangoproject.com/ticket/27996>
Django <https://code.djangoproject.com/>
The Web framework for perfectionists with deadlines.
--
You received this message because you are subscribed to the Google Groups
"Django updates" 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].
To view this discussion on the web visit
https://groups.google.com/d/msgid/django-updates/052.99e796b54bb7e4cef01431cbeab273a7%40djangoproject.com.
For more options, visit https://groups.google.com/d/optout.
