Android : Which way is better accesing android sqlitehelper object from multiple locations?

Assume i will store Students, Employees, Teachers etc.

Should i create 3 tables in one database or should i create a database for each above object.

• 
  

  If i choose to use the way one, i need to use one instance of sqlitehelper in all parts of my app. So my classes which dies insert, update, delete operations must access that object all the time so a little bit extra coding which should be fine.

  
  


• 
  

  If second way, then i don't need to do anything, just create separate classes and not having to worry about anything. Or is it? Is creating databases for one table or similar conditions good practice? Is it
  
  bad for phone performance

  
  

?

What do you suggest for that?