SelectWithUnionQuery (children 1)
 ExpressionList (children 1)
  SelectQuery (children 3)
   ExpressionList (children 1)
    Identifier f2
   TablesInSelectQuery (children 1)
    TablesInSelectQueryElement (children 1)
     TableExpression (children 1)
      Function merge (children 1)
       ExpressionList (children 2)
        Function currentDatabase (children 1)
         ExpressionList
        Literal \'^abc$\'
   Function and (children 1)
    ExpressionList (children 3)
     Function equals (children 1)
      ExpressionList (children 2)
       Identifier _table
       Literal \'abc\'
     Function equals (children 1)
      ExpressionList (children 2)
       Identifier f1
       Literal \'a\'
     Function less (children 1)
      ExpressionList (children 2)
       Function modulo (children 1)
        ExpressionList (children 2)
         Function rand (children 1)
          ExpressionList
         Literal UInt64_100
       Literal UInt64_20
