low_value、high_value

直方图中有low_value、high_value值，如果显示为10进制可以使用下面方法：

字符串

select utl_raw.cast_to_number(low_value) from dual;


declare n varchar2(2000);
 begin
 dbms_stats.convert_raw_value('100001',n);
 dbms_output.put_line(n);
 end;
/

时间类型转换

SQL> set serveroutput on
SQL> declare
  v_x date;
  v_result varchar2(400);    
  begin
    dbms_stats.convert_raw_value('08080640033C04',v_x);
    select to_char(v_x,'yyyy-mm-dd hh24:mi:ss') into v_result from dual;
    dbms_output.put_line(v_result);
  end;
/


declare
d date;
begin
   dbms_stats.convert_raw_value (hextoraw('7876070A010101'), d);
   dbms_output.put_line (d);
end;
/

通用转换function

create or replace function display_raw (rawval raw, type varchar2)
return varchar2
is
   cn     number;
   cv     varchar2(32);
   cd     date;
   cnv    nvarchar2(32);
   cr     rowid;
   cc     char(32);
begin
  if (type = 'NUMBER') then
     dbms_stats.convert_raw_value(rawval, cn);
     return to_char(cn);
  elsif (type = 'VARCHAR2') then
     dbms_stats.convert_raw_value(rawval, cv);
     return to_char(cv);
  elsif (type = 'DATE') then
     dbms_stats.convert_raw_value(rawval, cd);
     return to_char(cd);
  elsif (type = 'NVARCHAR2') then
     dbms_stats.convert_raw_value(rawval, cnv);
     return to_char(cnv);
  elsif (type = 'ROWID') then
     dbms_stats.convert_raw_value(rawval, cr);
     return to_char(cnv);
  elsif (type = 'CHAR') then
     dbms_stats.convert_raw_value(rawval, cc);
     return to_char(cc);
  else
     return 'UNKNOWN DATATYPE';
  end if;
end;
/

​​http://structureddata.org/2007/10/16/how-to-display-high_valuelow_value-columns-from-user_tab_col_statistics/​​

​​https://stackoverflow.com/questions/20462309/oracle-convert-raw-to-date-format​​

​其他

查看分区表的high_value

CREATE OR REPLACE function long_2_varchar (
p_table_owner    in DBA_TAB_PARTITIONS.table_owner%type,
p_table_name     in DBA_TAB_PARTITIONS.table_name%type,
p_partition_name in DBA_TAB_PARTITIONS.partition_name%type) 
return varchar2
as
l_high_value LONG;
begin
    select high_value
    into l_high_value      
    from DBA_TAB_PARTITIONS
    where table_owner = p_table_owner
    and table_name  = p_table_name and partition_name = p_partition_name;
return substr( l_high_value, 1, 4000 );
end;
/

dum转换

SQL> select dump(1234,16) from dual;

DUMP(1234,16)
--------------------
Typ=2 Len=3: c2,d,23

SQL> set serveroutput on 
SQL> declare n number;
begin
 dbms_stats.convert_raw_value('c20d23',n);
 dbms_output.put_line(n);
end;
/  2    3    4    5    6
1234