Compare two records

[baotrung]

Hi all,
I have a table to store information about one person(firstname,lastname,birthday,sex,address,...). My table have a lot of record (about 1000000 rec). Could you show me how to compare one record with the other in this table(to count the number of the same column)? I have tried to test compare but it very slowly. I think my algorithm is not optimal.
Can you help me?(show me the algorithm) Thanks!
Trung

[slimdave]

Can you give an example of what you want to do?

[jovery]

Please only post your questions in ONE forum!

[baotrung]

for example: I have a table Customer(firstname varchar2(20),
lastname varchar2(20),
sex number,
address varchar2(255)
.......................)
I want compare a record with other record in this table. I write a function:
Function Compare(rowid1 varchar2,rowid2 varchar2) return number is
str1 varchar2(255);
str2 varchar2(255);
v_value1 varchar2(100);
v_value2 varchar2(100);
n_count number:=0;
Begin
str1:='select firstname from customer where rowid=''rowid1''';
str2:='select firstname from customer where rowid=''rowid2''';
execute str1 into v_value1;
execute str1 into v_value2;
if str1=str2 then
n_count:=n_count+1;
end if;
--similar with other column: lastname,sex,address...
return n_count;
End;

But when the number of record is too big(about 1000000 record) then the speed is very bad, very slow. Can you show me another algorithm?
Thanks!
Trung

[ocp9999]

Do a self join - should run faster than PL SQL:

select count(a.rowid) from cust a, cust b
where a.fname = b.fname

This should give all rows with same fname. try.