CreateQuery sample_merge_tree (children 3)
 Identifier sample_merge_tree
 Columns definition (children 1)
  ExpressionList (children 2)
   ColumnDeclaration dt (children 1)
    DataType DateTime
   ColumnDeclaration x (children 1)
    DataType UInt64
 Storage definition (children 4)
  Function MergeTree
  Function toYYYYMMDD (children 1)
   ExpressionList (children 1)
    Identifier dt
  Identifier x
  Set
