[wp-trac] [WordPress Trac] #48285: wp-config-sample.php should default to `utf8mb4` instead of `utf8` character set

[WordPress Trac]

#48285: wp-config-sample.php should default to `utf8mb4` instead of `utf8`
character set
-------------------------+------------------------------
 Reporter:  bchecketts   |       Owner:  (none)
     Type:  enhancement  |      Status:  assigned
 Priority:  normal       |   Milestone:  Awaiting Review
Component:  Database     |     Version:  5.3
 Severity:  minor        |  Resolution:
 Keywords:  has-patch    |     Focuses:
-------------------------+------------------------------

Comment (by SergeyBiryukov):

 Replying to [comment:3 JavierCasares]:
 > Right now, with the latest MySQL 8.0 and MariaDB 10.6 versions, there is
 no "utf8" because hey changed it for "utf8mb3".

 Thanks! This should now be addressed in #53623.

 > If we want to support all the international language charset, WordPress
 should support by default "utf8mb4" (supported by all WordPress-SQL
 supported databases).

 As noted in comment:1 and comment:2, WordPress does automatically upgrade
 to `utf8mb4` when possible.

 Replying to [comment:8 JavierCasares]:
 > Based on this, yes, new versions of WordPress may have utf8mb4 by
 default.

 I might be missing something, but as noted in comment:7, WordPress still
 has MySQL 5.0 as a minimum requirement at this time, which did not include
 `utf8mb4`. So it looks like until the minimum version is bumped to MySQL
 5.5, it is neither safe nor required to change the default charset in `wp-
 config-sample.php`.

 On a related note, reading the MariaDB ticket
 [https://jira.mariadb.org/browse/MDEV-8334 MDEV-8334 Rename utf8 to
 utf8mb3]:
 > In long terms we want the name `utf8` mean the full featured UTF-8.
 > We'll do a few preparatory steps:
 >
 > 1. Change the main name of the 3-byte character set from `utf8` to
 `utf8mb3` and make `utf8` alias for `utf8mb3`. This will change all `SHOW`
 and `INFORMATION_SCHEMA` output to display `utf8mb3` instead of `utf8`, as
 well as change `mysqldump` to dump `utf8mb3` instead of just `utf8`.
 > 2. Add a new server option, say `--utf8-is-utf8mb3`, which will be
 `true` by default, but the DBA will be able to change it to false and thus
 make `utf8` mean `utf8mb4`.
 > 3. A few releases later we'll change `--utf8-is-utf8mb3` to be `false`
 by default.
 >
 > Or
 >
 > 2. Do not add any new server options and
 > 3. Add a new `old_mode` value for reverting `utf8` to `utf8mb3` when the
 default will mean `utf8mb4`.

 The latter appears to be [https://mariadb.com/kb/en/mariadb-1061-release-
 notes/#character-sets implemented in MariaDB 10.6.1].

 Also reading the MySQL note on [https://dev.mysql.com/doc/refman/8.0/en
 /charset-unicode-utf8mb3.html The utf8mb3 Character Set (3-Byte UTF-8
 Unicode Encoding)]:
 > Historically, MySQL has used `utf8` as an alias for `utf8mb3`; beginning
 with MySQL 8.0.28, `utf8mb3` is used exclusively in the output of `SHOW`
 statements and in Information Schema tables when this character set is
 meant.
 >
 > At some point in the future `utf8` is expected to become a reference to
 `utf8mb4`. To avoid ambiguity about the meaning of `utf8`, consider
 specifying `utf8mb4` explicitly for character set references instead of
 `utf8`.
 >
 > You should also be aware that the `utf8mb3` character set is deprecated
 and you should expect it to be removed in a future MySQL release. Please
 use `utf8mb4` instead.

 If the long-term goal of both projects is to make `utf8` an alias for
 `utf8mb4` as mentioned above, the default charset in `wp-config-
 sample.php` may not technically need any changes at all, though it still
 might be a good idea to explicitly change it to `utf8mb4` when the minimum
 version is bumped to MySQL 5.5.

-- 
Ticket URL: <https://core.trac.wordpress.org/ticket/48285#comment:10>
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