CreateQuery foo (children 3)
 Identifier foo
 Columns definition (children 1)
  ExpressionList (children 2)
   ColumnDeclaration id (children 1)
    DataType UInt64
   ColumnDeclaration key (children 1)
    DataType AggregateFunction (children 1)
     ExpressionList (children 2)
      Identifier max
      DataType UInt64
 Storage definition (children 2)
  Function MergeTree
  Identifier key
