#32691: Django 3.2 boolean field SQL output is causing a performance regression
in
MySQL.
-------------------------------------+-------------------------------------
Reporter: Todor Velichkov | Owner: nobody
Type: | Status: closed
Cleanup/optimization |
Component: Database layer | Version: 3.2
(models, ORM) |
Severity: Normal | Resolution: invalid
Keywords: bool, booleanfield, | Triage Stage:
orm, sql, mysql | Unreviewed
Has patch: 0 | Needs documentation: 0
Needs tests: 0 | Patch needs improvement: 0
Easy pickings: 0 | UI/UX: 0
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Comment (by Todor Velichkov):
Hi Mariusz,
I don't quite agree, both clauses are syntactically correct yes, but they
are not the same.
MySQL does not have a boolean type of column, so Django is using
[https://docs.oracle.com/cd/E17952_01/mysql-8.0-en/integer-types.html
tinyint]
which stores value between `-128..127` or `0..255`
When you tell `mysql` you are looking for {{{`mytable`.`myfield`}}} this
basically translates to all values between `-128..127` except `0` which is
a range query equivalent to `myfield__in=[-128..-1]+[1..127]`
even `myfield__exact` lookup is acting the same way.
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Ticket URL: <https://code.djangoproject.com/ticket/32691#comment:3>
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