It makes me feel bad since I have to change my system to adapt some database defects, if there are. I use Oracle to development for quite a while. I...

Dave, I think you are right. I checked the information you hinted me. It is helpful. But the database reponses no change after I modified the database option. Here is...

Thanks,Mike.

Yes. I understand performance tuning does not deal with creating an index only. I just put the question to extreme. The execution plan contradicts my...

So, why do we continue to create an index on those non-primary-keys columns? Just a primary key would safeguard the better execution plan since whether...

Thanks, AJ.

Your meaning is Sql-Server do execute a TABLE SCAN, but on the index not on the real table, so Sql-Server still call this 'Clustered Index Scan'. But I don...