id	summary	reporter	owner	description	type	status	component	version	severity	resolution	keywords	cc	stage	has_patch	needs_docs	needs_tests	needs_better_patch	easy	ui_ux
31758	remove BytesToCharFieldConversionMixin	Sergey Fedoseev	Sergey Fedoseev	"`BytesToCharFieldConversionMixin` was added in 6141c752fe7091d2197f5ac061300a9e0a36b09b in order to fix #29251. It looks like the issue was caused by bug in mysqlclient and was fixed in [https://github.com/PyMySQL/mysqlclient-python/commit/73ccdcdddf2dd8e193e8af4a2362727c601b40ac 1.3.13]. Since we support mysqlclient >= 1.4, `BytesToCharFieldConversionMixin` could be removed.

This makes `Repeat` faster. Benchmarked on postgres with 10000 rows. Before:

{{{
In [8]: %timeit list(TestModel.objects.values_list(models.functions.Repeat(models.Value('a'), 2)))
18.1 ms ± 170 µs per loop (mean ± std. dev. of 7 runs, 100 loops each)
}}}

After:
{{{
In [3]: %timeit list(TestModel.objects.values_list(models.functions.Repeat(models.Value('a'), 2)))        
3.18 ms ± 28.5 µs per loop (mean ± std. dev. of 7 runs, 100 loops each)
}}}"	Cleanup/optimization	closed	Database layer (models, ORM)	dev	Normal	fixed			Accepted	1	0	0	0	0	0