CreateQuery tst (children 3)
 Identifier tst
 Columns definition (children 1)
  ExpressionList (children 2)
   ColumnDeclaration timestamp (children 1)
    DataType DateTime
   ColumnDeclaration val (children 1)
    DataType Nullable (children 1)
     ExpressionList (children 1)
      DataType Int8
 Storage definition (children 3)
  Function SummingMergeTree
  Function toYYYYMM (children 1)
   ExpressionList (children 1)
    Identifier timestamp
  Identifier timestamp
