Answer / manoj

primary key is a key which always accept unique value.

secondary key is a key which when you are making primary key
for more than one column as primary key for retrieving of
reords.
eg.
create table tnam
(ano number,
bno number,
bname char(12),
primary key(ano,bno))

In this bno is secondary key.

Answer / renu kakkar

PRIMARY REPRESENTS THE ROW/TUPPLE UNIQUELY WHEREAS
SECONDARY KEY REPRESENTS THE SET OF TUPPLES
EMPLOY_ID IS A PRIMARY KEY AND EMPLOY_DEPTT. IS A SECONDARY
KEY.

How can the performance of a trigger be improved?

0 Answers  

---

What is dba in sql? : SQL DBA

0 Answers  

---

What is the most restrictive isolation level? : Transact sql

0 Answers  

---

what is single byte over head in oracle..?

0 Answers  

---

What is the difference between instead of trigger and after trigger?

0 Answers  

---

what is difference between decode and case function?

2 Answers  

---

how can we find the select statement is indexed or not?

3 Answers   CTS,

---

What is bind variable in pl sql?

0 Answers  

---

I have a small PL/SQL Block assume in this way begin select * from emp where empno=100; exception when others then <Some Messages> when no_data_found then <Some Messages> when too_many_rows then <Some Messages> end; The question which he asked was whether this block will get executed normally or it will throw error ? If errored out then what is the reason for the error ? Could anybody please help me ? Regards Nakul Venkataraman

3 Answers   Satyam,

---

What is the use of non clustered index?

0 Answers  

---

is mysql query is case sensitive? : Sql dba

0 Answers  

---

Can you alter start with clause?

1 Answers   TCS,

---