AlterQuery  tab (children 2)
 ExpressionList (children 1)
  AlterCommand ADD_INDEX (children 1)
   Index (children 2)
    Identifier str
    Function text (children 1)
     ExpressionList (children 1)
      Function equals (children 1)
       ExpressionList (children 2)
        Identifier tokenizer
        Function ngrams (children 1)
         ExpressionList (children 1)
          Literal UInt64_3
 Identifier tab