Hi Tom,

First of all I personally thank you (and of course I believe that others do) for all the support you have given to us in giving us this opportunity to post questions thru this site.


Now with my concern:

1. I understand that constraints enforces business rule in my database and indexes gives our queries makes much faster if we create and index to a table.

My question is, what is the relationship between this 2.
For example :

SQL> create table online_tb (seq_no number, trun_num number, head varchar2(20) constraint NN NOT NULL, tran_Date date);

then,
alter table online_tb add constraint ol_tb_uk1
unique (seq_no,trun_num, head);

SQL> select uniqueness,index_name from user_indexes where table_name='ONLINE_TB';

UNIQUENES INDEX_NAME
--------- ------------------------------
UNIQUE OL_TB_UK1

SQL> SELECT CONSTRAINT_NAME, TABLE_NAME FROM USER_CONSTRAINTS WHERE TABLE_NAME='ONLINE_TB';

CONSTRAINT_NAME TABLE_NAME
------------------------------ ------------------------------
NN ONLINE_TB
OL_TB_UK1 ONLINE_TB

SQL> ALTER TABLE ONLINE_tB ADD CONSTRAINT OL_TB_PK1 PRIMARY KEY (SEQ_NO,TRUN_NUM,HEAD);
ALTER TABLE ONLINE_tB ADD CONSTRAINT OL_TB_PK1 PRIMARY KEY (SEQ_NO,TRUN_NUM,HEAD)
*
ERROR at line 1:
ORA-02261: such unique or primary key already exists in the table


SQL> CREATE UNIQUE INDEX OL_TB_UNIQ ON ONLINE_TB (SEQ_NO,TRUN_NUM,HEAD);
CREATE UNIQUE INDEX OL_TB_UNIQ ON ONLINE_TB (SEQ_NO,TRUN_NUM,HEAD)
*
ERROR at line 1:
ORA-01408: such column list already indexed

And if I create a UNIQUE INDEX on that same columns it gives me an error, Can you explain to me y?


2. We are receiving an error :
'ASSERTION FAILED'
PROGRAM : C:\ORANT\BIN\ifrun60.exe
FILE : e:\f994w32\src\if\iff\ifrlf.c
LINE : 890

Thank you very much and more power.