Interview Questions Answers in Oracle General, Cognos, Data Warehouse General, SQL PLSQL, DB2

Question { NIIT, 17663 }

how many columns can a plsql table have

Answer

A plsql table can hold to a maximum of 1000 columns.

Is This Answer Correct ?

13 Yes

4 No

Question { 4980 }

where do we see the run time of the report ?

Answer

1. drag a lay out calculation on the report header or footer
2. From the Function tab drag the As of Time()and drop in
the expression window
3. Click ok

Then run the report and it will display the report running
time

Is This Answer Correct ?

2 Yes

0 No

Question { HCL, 8369 }

how many types of formats you can run a report using cognos?

Answer

There are generally 7 types of report formats we can use to
run the report

1. HTML
2. PDF
3. Excel 2007
4. Excel 2002
5. Excel 2000 (single sheet)
6. CSV
7. XML

Is This Answer Correct ?

2 Yes

0 No

Question { 17351 }

What is the "junk dimension"? Give with examples?

Answer

A junk dimention table is a collection of junk dimentioms.
The Dimentions which are not related to any fact tables is
known as ju;nk dimention.Generally it is used to provide
extra informations.

Is This Answer Correct ?

4 Yes

3 No

Question { UST, 15827 }

how to delete duplicate rows from a specified table(only
single table)
how do you know which join is need to be used

Answer

DELETE FROM tablename A WHERE ROWID>(SELECT MIN(ROWID) FROM
tablename B WHERE A.key_values=B.key_values);

Is This Answer Correct ?

6 Yes

2 No

Question { HCL, 9190 }

1.WHAT IS DATA MART ?

Answer

Datamart is a subset of an Enterprise DataWareHouse.

Generally it contains subject oriented information means it
relates to specific deprtment like sales dept,human resource
dept,tax dept. etc of an organisation.

Is This Answer Correct ?

6 Yes

0 No

Question { Accenture, 11761 }

3.What is fact less fact ?

Answer

A fact table contains only the keys ie foreign keys but no
measures(numerics) is known as factless fact table.

A Fact Table having no Facts is known as Factless Fact
Table.

Is This Answer Correct ?

8 Yes

1 No

Question { IBM, 9472 }

4.Explain Snowflkeschema ?

Answer

In snowflake schema the dimension table(denormalized table)
will be further divided into one or more dimentions
(normalized tables) to organize the infomation in a better
structural format.To design snowflake we should first
design star schema design.

Is This Answer Correct ?

1 Yes

0 No

Question { ACS, 12169 }

What is Factless fact table? In which purpose we are using
this in our DWH projects?Plz give me the proper answer.

Thanks,
Ramesh

Answer

A Factless fact table contains only the keys but there is
no measures or in other way we can say that it contains no
facts.

Generally it is used to intigrate the fact tables.

Is This Answer Correct ?

11 Yes

2 No

Question { IBM, 8664 }

If a table column has is UNIQUE and has NOT NULL, is it
equivalent to a PRIMARY KEY column?

Answer

no. bcoz we can insert null values in the column which
contains the combination of constraints as
UNIQUE+ NOT NULL

but in case of primary key we can't use null values in that
primary key column

Is This Answer Correct ?

2 Yes

8 No

Question { Cap Gemini, 9757 }

what is differnece between DROP TABLE & DELETE TABLE .

Answer

in DROP TABLE command it will remove the table containts as
well as table structure from the database catalog, also it
release all the storage space it has acquired previously.
we can't rollback it as it is a ddl command.

but in case of DELETE TABLE command it just delete all the
records but not relaese the spaces it acquires .it can be
rollback as it is a dml command.

Is This Answer Correct ?

17 Yes

0 No

Question { 18219 }

Use of Text Source Variable in Report Studio?

Answer

The text source variable is used for conditional formatting.
The text source variable is used to display the text source
values in the place of numerics value.

Eg:
IF revenue>50000 THEN ('high')
ELSE ('low')

Here 'high' and 'low' are text source variables.

Is This Answer Correct ?

12 Yes

2 No

samir kumar sahoo