Ejabberd and MySQL DB problem with efficiency

Hello!

I have Ubuntu server x64 and MySql 5.5.47.

I want to store all messages on MySql. For this I've uncomment

odbc_type:mysql
odbc_server:localhost
odbc_database:xampp
odbc_username:username
odbc_password: password

in ejabberd.yml file.

And also set:
mod_mam:
db_type:odbc
default:always

After this I've restarted the server. I found that client is sending one messages for 3 minutes.
I've cheked "archive" table in my databes. Archive is empty.

I was trying to change database from MySQL to default Mnesia. It work's great. But I need MySql.

So, what's my mistake?