Inserting data with the help of nested table...!!!

Question

The following block is giving error
ORA-06502: PL/SQL: numeric or value error
the signature and signature_bkp have the same structure
So, can anybody help me out to solve this issue :
for copying records from one table to another table
Thanking You advancely
DECLARE
CURSOR c1
IS
SELECT *
FROM signature
WHERE creation_time > TRUNC ( SYSDATE ) - 100
AND ROWNUM < 102;
TYPE sig_typ IS TABLE OF signature%ROWTYPE;
sig_t sig_typ;
BEGIN
OPEN c1;
FETCH c1
BULK COLLECT INTO sig_t;
CLOSE c1;
FORALL i IN sig_t.FIRST .. sig_t.LAST
INSERT INTO signature_bkp
VALUES sig_t ( i );
COMMIT;
END;
--DKar                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                   

Answer 1

Or whether a INSERT statement with SELECT clause will do that for youby using this technique, it took 47:08:45 to copy 7252 rows
and by using a cursor for loop took 49:03:23 to copy 13567 rows
So there was appox. 40% increase in performance by using pl/sql. I thought it could be even faster using the bulk-bind ing features and nested tables.
OR i just want to know ....how to correct the block of code that was given in my 1st msg without changing its logic.
Thanks
--DKar