Oracle: DBA_TAB_COLS

Columns related to statistics

with
--
--     Define a few functions to convert the raw values of low_value and high_value
--     to a humanly readable text.
--
   function rawToDate (r in raw) return varchar2 as
      dt date;
   begin
       dbms_stats.convert_raw_value(r, dt);
       return to_char(dt, 'yyyy-mm-dd hh24:mi:ss');
   end rawToDate;

   function rawToBinaryFloat (r in raw) return varchar2 as
       flt binary_float;
   begin
       dbms_stats.convert_raw_value(r, flt);
       return to_char(flt);
   end rawToBinaryFloat;

   function rawToBinaryDouble (r in raw) return varchar2 as
       dbl binary_double;
   begin
       dbms_stats.convert_raw_value(r, dbl);
       return to_char(dbl);
   end rawToBinaryDouble;      

select
   case col.data_type
        when 'NUMBER'        then to_char(utl_raw.cast_to_number  (col.low_value))
        when 'VARCHAR2'      then utl_raw.cast_to_varchar2        (col.low_value)
        when 'DATE'          then rawToDate                       (col.low_value)
        when 'CLOB'          then utl_raw.cast_to_varchar2        (col.low_value)     -- Does not seem to work!
        when 'BINARY_FLOAT'  then rawToBinaryFloat                (col.low_Value)
        when 'BINARY_DOUBLE' then rawToBinaryDouble               (col.low_Value)
        else                 rawtohex(col.low_value)
   end                                                                                   lowValue,
   --
   case col.data_type
        when 'NUMBER'        then to_char(utl_raw.cast_to_number  (col.high_value))
        when 'VARCHAR2'      then utl_raw.cast_to_varchar2        (col.high_value)
        when 'DATE'          then rawToDate                       (col.high_value)
        when 'CLOB'          then utl_raw.cast_to_varchar2        (col.high_value)     -- Does not seem to work!
        when 'BINARY_FLOAT'  then rawToBinaryFloat                (col.high_value)
        when 'BINARY_DOUBLE' then rawToBinaryDouble               (col.high_value)
        else                 rawtohex(col.low_value)
   end                                                                                   highValue,   
   --
   col.low_value,
   col.high_value,
   col.sample_size,
   col.num_distinct,
   col.num_buckets,
   col.avg_col_len,
   col.density,
   col.histogram,
   col.global_stats,
   col.user_stats,
   col.*
from
   dba_tab_cols        col
where
   col.owner      =  user       and
   col.table_name = 'TQ84_T';

drop table tq84_t;
create table tq84_t (
   id    number,
   txt   varchar2(10),
   dt    date,
   flt   binary_float,
   dbl   binary_double,
   ch    char(10),
   clb   clob
);

insert into tq84_t values (  42, 'forty-two', '2021-08-28 22:23:24', 9.9, -7.7, 'xyz', 'the lob'    );
insert into tq84_t values (  17, 'seventeen', '2017-08-28 22:23:24',-9.9,  7.7, 'abc', 'another lob');

begin
    dbms_stats.gather_table_stats(user, 'TQ84_T', method_opt=>'for all columns');
end;
/

See also