Answer Posted / asnani_satish@yahoo.com

Difference between sub-query, correlated query and query as
table
1. Sub-query : the inner query is executed in entirety
before the outer query is executed
eg select * from emp where deptno in (select deptno from dept);

2. Correlated Query: For each record fetched in outer query
corresponding matching records are fetched in sub-query
because of join condition within inner sub-query. Answers
1,2,3 are correct

3. Query as Table: A query can behave as a table

select a.empno,a.sal,a.sal/b.avgsal*100 as percent_avg_sal
from emp a,(select deptno,sum(sal) avgsal from emp group by
deptno) b
where a.deptno=b.deptno;

Here the entire "(select deptno,avg(sal).....)" behaves as
table named "b". The query is behaving as a temporary table.

Which join is like inner join?

974

---

What is the difference between mdf and ndf files?

1061

---

Are views faster than queries?

917

---

How to rename a table?

956

---

What are the types of queries in sql?

1015

---

Which are the different types of indexes in sql?

991

---

What are the parts of a sql statement?

1028

---

What is sql partition function?

1116

---

How to select unique records from a table?

999

---

what is sp_pkeys? : Transact sql

1102

---

How to avoid using cursors? What to use instead of cursor and in what cases to do so?

1124

---

What is the difference between clustered and non-clustered index in sql?

957

---

Write an sql query to select all records from the table?

968

---

What is interval partition?

986

---

How do I view a sql trace file?

960

---