CreateQuery t (children 3)
 Identifier t
 Columns definition (children 2)
  ExpressionList (children 3)
   ColumnDeclaration key (children 1)
    DataType UInt32
   ColumnDeclaration created_at (children 1)
    DataType Date
   ColumnDeclaration value (children 1)
    DataType UInt32
  ExpressionList (children 1)
   Projection (children 1)
    ProjectionSelectQuery (children 2)
     ExpressionList (children 3)
      Identifier key
      Identifier created_at
      Function sum (children 1)
       ExpressionList (children 1)
        Identifier value
     ExpressionList (children 2)
      Identifier key
      Identifier created_at
 Storage definition (children 3)
  Function MergeTree
  Function toYYYYMM (children 1)
   ExpressionList (children 1)
    Identifier created_at
  Identifier key