Answer Posted / 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.

What are the features of pl sql?

767

---

Is coalesce faster than isnull?

701

---

Explain alias in sql?

765

---

how to convert character strings to numeric values? : Sql dba

771

---

What are its different types of dbms?

714

---

---

What is an inner join sql?

694

---

what is uncommittable transactions? : Transact sql

752

---

what is single byte over head in oracle..?

2090

---

How many tables can a sql database have?

710

---

what is log shipping? : Sql dba

822

---

What are the types of sql commands?

741

---

What is a natural join sql?

705

---

Can we have two clustered index on a table?

760

---

what is foreign key? : Sql dba

750

---

How to run sql commands in sql*plus?

784

---