Performance issues

[arvas]

Hi, my performance for otrs shows the following issues:

1 Failed Check the utf8 table charset collation.
Your charset collation is set to Invalid charset collation for: article_attachment[].

2 Critical Search for invalid user with locked tickets.
Is there any way to run a generic query or mysql command to unlock such users?

3Check if the system uses Apache::DBI.

Apache::DBI should be used to get a better performance (pre-establish database connections).

Can i accomplish this connection on windows or do i need to use linux?

Thanks for your reading!