Change IS_DEFAULT value for INFORMATION_SCHEMA.COLLATIONS

There is no a way to change the default collation for a character set. Default collations are hard-coded. For example, utf8_general_ci is the hard-coded default collation for the character set utf8.

This is a missing feature.

The SQL standard has "CREATE CHARACTER SET" statement for this: https://kb.askmonty.org/en/create-character-set-statement/

So one can do:

CREATE CHARACTER SET utf8my AS GET utf8 COLLATE utf8_unicode_ci;

and then use this:

SET NAMES utf8my;

which effectively sets the connection character set to utf8, and the collation to utf8_unicode_ci.

MariaDB does not support CREATE CHARACTER SET yet.

The only workaround is to make the application send:

SET NAMES utf8 COLLATE utf8_unicode_ci;

instead of just:

SET NAMES utf8;