This can replace DBX, which was taken out of the core PHP, and has not been updated since 2011.

https://pecl.php.net/package/dbx

Seems there was a battle between DBX and PDO that we didn't notice.

I don't think we really care about PDO, but I want to track this. I've never encountered a server without a native MySQL extension if it has MySQL on it. And for PostgreSQL or SQL Server or Oracle, you can expect to use the native extension also (with the exception that SQL Server accessed from a Linux or Mac box will have to use ODBC, which I have just implemented).

A user in here had a crash with mysqli https://compo.sr/forum/topicview/browse/deploying/error-503-showing-up.htm?post_id=5095&redirected=1#post_5095
This could not be resolved without forcing the code to not be type-strict (i.e. not reading in mysql field metadata).

Therefore I've now implemented a mysql_pdo database driver to see if this can work as a substitute on his server.

Server instability on particular DB client architectures is possible due to all the plumbing involved.