Do I need to used a Synchronized statement every time I read/write to my database?

Question

I'm implementing Android Backup Service and the guide says that

reading and writing to external storage is not threadsafe

It then says that the onBackup and onRestore functions should be performed in a synchronized statement. My question is: do I need to use this approach everywhere I read/write my database?

So

db.open();
course = db.getCourse(courseId);
db.close();

would become...

synchronized(MyConstants.DBContant){
    db.open();
    course = db.getCourse(courseId);
    db.close();
}

I read/write to my db a lot. I want to make sure before I go add this everywhere.