AlterQuery  t1 (children 3)
 ExpressionList (children 1)
  AlterCommand MODIFY_COLUMN (children 1)
   ColumnDeclaration a (children 2)
    DataType Float64
    Function plus (children 1)
     ExpressionList (children 2)
      Function toDateTime (children 1)
       ExpressionList (children 1)
        Identifier b
      Function toIntervalMonth (children 1)
       ExpressionList (children 2)
        Function viewExplain (children 1)
         ExpressionList (children 3)
          Literal \'EXPLAIN\'
          Literal \'actions = 1\'
          Subquery (children 1)
           SelectWithUnionQuery (children 1)
            ExpressionList (children 1)
             SelectQuery (children 3)
              ExpressionList (children 2)
               Function toIntervalMonth (children 1)
                ExpressionList (children 1)
                 Literal UInt64_1
               Literal UInt64_2
              TablesInSelectQuery (children 1)
               TablesInSelectQueryElement (children 1)
                TableExpression (children 1)
                 TableIdentifier t1__fuzz_26
              ExpressionList (children 2)
               Function toFixedString (children 1)
                ExpressionList (children 2)
                 Literal \'%Prewhere%\'
                 Literal UInt64_10
               Function toNullable (children 1)
                ExpressionList (children 1)
                 Literal UInt64_12
        Literal UInt64_1
 Identifier t1
 Set
