CreateQuery alter_test (children 3)
 Identifier alter_test
 Columns definition (children 1)
  ExpressionList (children 2)
   ColumnDeclaration a (children 1)
    DataType Int32
   ColumnDeclaration b (children 1)
    DataType DateTime
 Storage definition (children 2)
  Function ReplacingMergeTree (children 1)
   ExpressionList (children 1)
    Identifier b
  Identifier a
