CreateQuery mt_table (children 3)
 Identifier mt_table
 Columns definition (children 1)
  ExpressionList (children 3)
   ColumnDeclaration d (children 1)
    DataType Date
   ColumnDeclaration key (children 1)
    DataType UInt64
   ColumnDeclaration data (children 1)
    DataType String
 Storage definition (children 3)
  Function MergeTree (children 1)
   ExpressionList
  Function toYYYYMM (children 1)
   ExpressionList (children 1)
    Identifier d
  Identifier key