Select * FROM command is not working :(

[jgangulli]

Hi, from last few days I'm working on it and I'm successfully able to insert data in my mysql and cassandra database but whenever I'm trying to execute select * from command it is showing planing not finishing it. and I'm not able to see table content.
I will be very thankful if someone can help me and can explain what are prestouser, prestoscema. I mean what exactly I have to give value for it in reference.yml file.

Thank you.