#35778: Use native JSONObject on Postgres 16+ with server side bindings
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Reporter: john-parton | Owner: john-
| parton
Type: New feature | Status: assigned
Component: Database layer | Version: dev
(models, ORM) |
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
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Comment (by Simon Charette):
Another con of changing `::` at this point is that will change the SQL
generated in any usage `Cast` in expression indices which might cause
people these indices not to be used anymore when users upgrade their
version of Django.
For example, say that you have a model of the form
{{{#!python
class People(models.Model):
phone_number = models.IntegerField()
class Meta:
indexes = [
Index(name="phone_number_str", Cast("phone_number",
models.TextField()))
]
}}}
Then the resulting index will be on `(phone_number)::text` and queries of
the form `filter(phone_number__startswith="123")` will generate `WHERE
(phone_number)::text LIKE '123%'` will be able to use the index.
If we change `Cast` to use `CAST` instead of `::` are confident that the
Postgres planer will be smart enough to use the pre-existing
`(phone_number)::text` it for queries of the form `CAST(phone_number AS
text) LIKE '123%'`? From past experience the expression has to exactly
match for the planner to consider the index and we can't expect users to
rebuild all of their indices every time they upgrade their Django version.
--
Ticket URL: <https://code.djangoproject.com/ticket/35778#comment:11>
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