[Django] #35717: Reduce CreateCollation + RemoveCollation to nothing

[Django]

#35717: Reduce CreateCollation + RemoveCollation to nothing
-------------------------------------+-------------------------------------
Reporter: Adam | Owner: Adam Johnson
Johnson |
Type: | Status: assigned
Cleanup/optimization |
Component: | Version: dev
Migrations |
Severity: Normal | Keywords:
Triage Stage: | Has patch: 0
Unreviewed |
Needs documentation: 0 | Needs tests: 0
Patch needs improvement: 0 | Easy pickings: 0
UI/UX: 0 |
-------------------------------------+-------------------------------------
These Postgres-specific operations should optimize into nothing, if they
create and remove the same collation.

I believe we need to implement `CreateCollation.reduce()` that returns an
empty list when the other operation is a `RemoveCollation` for the same
`(locale, provider, deterministic)` tuple. This can take inspiration from
`CreateModel.reduce()` which does similar when reducing to a
`DeleteModel`.
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Ticket URL: <https://code.djangoproject.com/ticket/35717>
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[Django]

#35717: Reduce CreateCollation + RemoveCollation to nothing
-------------------------------------+-------------------------------------

Reporter: Adam Johnson | Owner: Adam
Type: | Johnson
Cleanup/optimization | Status: assigned
Component: Migrations | Version: dev
Severity: Normal | Resolution:
Keywords: | Triage Stage: Accepted
Has patch: 1 | Needs documentation: 0

Needs tests: 0 | Patch needs improvement: 0
Easy pickings: 0 | UI/UX: 0
-------------------------------------+-------------------------------------

Changes (by Sarah Boyce):

* has_patch: 0 => 1
* stage: Unreviewed => Accepted

Comment:

Thank you! [https://github.com/django/django/pull/18524 PR]
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Ticket URL: <https://code.djangoproject.com/ticket/35717#comment:1>

[Django]

#35717: Reduce CreateCollation + RemoveCollation to nothing
-------------------------------------+-------------------------------------
Reporter: Adam Johnson | Owner: Adam
Type: | Johnson
Cleanup/optimization | Status: assigned
Component: Migrations | Version: dev
Severity: Normal | Resolution:

Keywords: | Triage Stage: Ready for
| checkin

Has patch: 1 | Needs documentation: 0
Needs tests: 0 | Patch needs improvement: 0
Easy pickings: 0 | UI/UX: 0
-------------------------------------+-------------------------------------

Changes (by Mariusz Felisiak):

* stage: Accepted => Ready for checkin

--
Ticket URL: <https://code.djangoproject.com/ticket/35717#comment:2>

[Django]

#35717: Reduce CreateCollation + RemoveCollation to nothing
-------------------------------------+-------------------------------------
Reporter: Adam Johnson | Owner: Adam
Type: | Johnson

Cleanup/optimization | Status: closed
Component: Migrations | Version: dev
Severity: Normal | Resolution: fixed

Keywords: | Triage Stage: Ready for
| checkin
Has patch: 1 | Needs documentation: 0
Needs tests: 0 | Patch needs improvement: 0
Easy pickings: 0 | UI/UX: 0
-------------------------------------+-------------------------------------

Changes (by Sarah Boyce <42296566+sarahboyce@…>):

* resolution: => fixed
* status: assigned => closed

Comment:

In [changeset:"cee95e6172f2ea3dbf8cfd4214562cfc92f95392" cee95e61]:
{{{#!CommitTicketReference repository=""
revision="cee95e6172f2ea3dbf8cfd4214562cfc92f95392"
Fixed #35717 -- Reduced Create/RemoveCollation operations when optimizing
migrations.
}}}
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Ticket URL: <https://code.djangoproject.com/ticket/35717#comment:3>