I don't know anything about INSTALL SOFILE, but we do have INSTALL SONAME 'foo'. It does not solve the problem with sql file, but it is platform-independent.

Sorry INTALL SOFILE is what I was referring to. Forgot the .so/.dll part is optional.

In Bug#73802 you specify to issues that a json file should solve:

• Many plugins have more than one function. Loading all functions takes one statement per function
• Loading plugins on Windows or Linux/UNIX is different (.so vs. .dll)

INSTALL SONAME fixes them both.

As for the "run sql file", I think it's the plugin job to install itself properly. I agree, that it's an open issue now. Ideally, I'd like a user to do INSTALL PLUGIN or INSTALL SONAME and the server would run necessary sql commands automatically. One of the issues to consider, if the plugin is loaded with --plugin-load command-line option, it'll be initialized before the server is ready to accept connections, that is, before the server is able to run plugin initialization sql script.

The json-file also serves another purpose: List not-yet-installed plugins, but that could also be rolled into INSTALL SONAME.
And what about plugins without a so-file? E.g.

# yum install mariadb-foobar-extension

# rpm -ql mariadb-foobar-extension

/plugin/dir/location/foobar_10_0.sql

/plugin/dir/location/foobar_10_1.sql

/plugin/dir/location/foobar_10_2.sql

/plugin/dir/location/foobar.json

mariadb> SHOW EXTENSIONS;

+----------------------------+----------+--------------------+-------------+---------+

| Name                       | Status   | Type               | Library     | License |

+----------------------------+----------+--------------------+-------------+---------+

| foobar                     | AVAILABLE   | SQL PACKAGE     | NULL        | MIT    |

…

+----------------------------+----------+--------------------+-------------+---------+

mariadb> INSTALL EXTENSION 'foobar';

(installs whatever .sql file(s) are appropriate)

Later update the RPM package and the json file gets updated and this triggers MariaDB to update the installed package/function/procedures/etc

I see. For not installed plugins you can use SHOW PLUGINS SONAME statement: https://mariadb.com/kb/en/mariadb/show-plugins-soname/

For packages, you're right, we don't have anything at the moment. There is MDEV-10591 in progress, though, and what one calls “a package” will clearly be influenced by it. I agree about ease of installing, etc, just let's revisit it when MDEV-10591 is closed.