AlterQuery  tab (children 2)
 ExpressionList (children 1)
  AlterCommand MODIFY_STATISTICS (children 1)
   Stat (children 2)
    ExpressionList (children 2)
     Identifier f64
     Identifier f32
    ExpressionList (children 2)
     Function tdigest (children 1)
      ExpressionList
     Function uniq (children 1)
      ExpressionList
 Identifier tab
