Answer / venkateshmalneni

EXIST is used as conditional operator in which u can write a query
IN is also used as a conditional operator in which we gives a list of elements

Answer / moorthy g

select ename from emp e
where mgr in (select empno from emp whereename = 'KING');

Here's the EXPLAIN PLAN for this query:

OBJECT OPERATION
---------- ----------------------------------------
SELECTSTATEMENT()
NESTEDLOOPS()
EMP TABLEACCESS(FULL)
EMP TABLEACCESS(BY INDEX ROWID)
PK_EMP INDEX(UNIQUESCAN)

This query is virtually equivalent to this:

select e1.ename from emp e1,(select empno from empwhere
ename = 'KING') e2
where e1.mgr = e2.empno;

You can write the same query using EXISTS bymoving the outer
query column to a subquery condition, likethis:

select ename from emp e
where exists (select 0 from emp wheree.mgr = empno and
ename = 'KING');

When you write EXISTS in a where clause, you'retelling the
optimizer that you want the outer query to be runfirst,
using each value to fetch a value from the inner
query(think: EXISTS = outside to inside).

Answer / sujeetha

It is almost similar to IN but the difference is that in
EXIST it will retrive the row atleast one row in the inner
query satisfies but in IN we can have manuy values

Answer / pavan_615

IN- sub Query - it will be executed once for the full query
Exist - Co-related sub Query - it will be executed for each
row.-- exist will me faster when you are working with big
tables.

Please explain in detail with example about 1.Confirmed Dimension. 2.Junk Dimension. 3.Degenerated Dimension. 4.Slowly changing Dimensions

3 Answers   Infotech,

---

why we use materialized view over view?

1 Answers   Zensar,

---

Can we create multiple integration service on single repository?

0 Answers  

---

source table have 3 records? and it is sucessfully loaded into target. and 4more records is added in to source .that means 7 records now in source. we have to load the remaining 4 records into the same trgt table with maintian top 3 records. how ?can any one give me the data flow of this logic plz?

5 Answers   Wipro,

---

I have been working in Informix-4gl for the past 2 years in an MNC company.But I'm interested to work in Business Intelligence tools. Is it possible to change the technology now? I'm really confused, please help me

1 Answers  

---

create a mapping to retrieve the employees who are getting salary greater than average salary?

4 Answers   TCS,

---

What is joiner cache?

2 Answers   TCS,

---

What do you mean incremental aggregation?

0 Answers  

---

can we use self join in informaitca?

3 Answers   IBM,

---

How would you join a node to the already existing domain?

0 Answers  

---

If you have 10 mappings designed and you need to implement some chages (may be in existing mapping or new mapping need to be designed) then how much time it takes from easier to complex?

1 Answers  

---

When do we use dynamic cache and static cache in connected and unconnected lookup transformations?

3 Answers  

---