Explain the normalization and why it is done. explain the case when we avoid the normalization in database.

ppad001

 Profile Answers by ppad001 Questions by ppad001

• Feb 27th, 2013

For perfomance optimization.
Like in case of datawarehousing operation the no of tables to be joined to get the desired output might be too high. In such a case we de-normalize to serve our purpose.

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Aria Ansari

• Nov 12th, 2013

It is about referential integrity or making data both reliable and Secure. As an example by applying a foreign key constrain between customer and order tables It will not be allowed to create an order...

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I want to add a new column in our table and i already have 4 column in table i want that my column should be added at 3rd position not in last position ..

S. Venmathi

• Jan 5th, 2015

if we are a Admin there is some possible. As my thought, it is not possible. but we can change the order of the column when we show the table. Example, consider your your fourth column is last_name, w...

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Elango

• Jan 23rd, 2015

PL/SQL packages are schema objects that groups logically related PL/SQL types, variables and subprograms. A package will have two mandatory parts: Package specification Package body or defi...

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kamlesh mishra

• May 18th, 2015

Default type of index is B-Tree - usually created when the column have more distinct or unique values like emp_no. When column have sequential values e.g 111,112,113,114 then use reverse key index wh...

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What is the use Index Organized Table (IOT)?

Vishal BHOSALE

• Nov 16th, 2015

Index-organized tables have full table functionality. They support features such as constraints, triggers, LOB and object columns, partitioning, parallel operations, online reorganization, and replica...

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How to delete duplicate records without using rownum/rowid concept?

cocoole

 Profile Answers by cocoole Questions by cocoole

• Jan 7th, 2016

Delete rowid not in (select the max rowid and group by each col {find the no duplicate table})

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If an implicit index is created when we create a primary key, then what is the need of explicit cursor?

shiva sai

• Feb 15th, 2016

1. Using implicit index the data can be fetched fastly only when the where clause has primary key column.

2. Explicit cursor is used when we want to fetch more than one record and also the where condition does not have primary column.

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Display employees who are IT_prog and salary is greater than 3000 and department is not equal to 80 and having the manager as 103

Neha

• May 26th, 2016

Code
 

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Compose an SQL statement to show a list of two least expensive vendors (suppliers) for each raw material. In the result table, show Material ID, Material Description, Vendor ID, Vendor Name, and Supplier’s unit price. Sort the result table by Material_ID and unit price in ascending order. Note: if a raw material has only one supplier(vendor), that vendor should also be in the result (output) table...

shirley

• Apr 26th, 2017

"sql SELECT Rank() OVER (PARTITION BY MaterialID ORDER BY UnitPrice ASC) AS [Ranking], MaterialID, Description, VendorID, VendorName, UnitPrice INTO tempdb..ProductByVendor FROM ...

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Describe use of VIEW in SQL Server?

Krishnaveni

• Aug 10th, 2018

A view is virtual table created using the real table. End users can easily access the data with out altering any table definition by using views. We can create, replace or drop the view depending on ...

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DROP TABLE &TABLE_NAME;Variable names should start with an alphabet. Here the table name starts with an '&' symbol.

Poonam Sachdeva

• Nov 23rd, 2005

This does not give an error in Oracle 9iFollowing is the outputSQL> DROP TABLE &TABLE_NAME;Enter value for table_name: temp_special_payslip(this has been eneterd by me)old   1: DROP TABLE &TABLE_NAMEnew   1: DROP TABLE temp_special_payslipTable dropped.

naveen

• Sep 19th, 2005

this works in oracle9i and it will ask for table nameand the given table will be deleted

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It is used to drop constraints specified on the table.

chitra

• Nov 14th, 2005

The rtrim function requires 1 arguments.

Anuradha

• Oct 13th, 2005

Ans:The given answer says the use of DROP command.but not the drop option in the ALTER TABLE command.       Drop option in the ALTER TABLE command is uesd to drop columns...

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FLOOR

Tushar

• May 9th, 2007

TRUNC will give same output as FLOOR

sahu

 Profile Answers by sahu Questions by sahu

• Jan 27th, 2006

Ans:Yes ,we can find the largest integer less than or equal to a specific valueFLOOR

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er.prateek.cs

 Profile Answers by er.prateek.cs Questions by er.prateek.cs

• May 28th, 2010

c>LIKE   LIKE%% with wildcards used for searching

kranti

• Jul 28th, 2005

LIKE

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How do I write a cron which will run a SQL query and mail the results to a group?

Kwisatz_Haderach

 Profile Answers by Kwisatz_Haderach Questions by Kwisatz_Haderach

• Feb 1st, 2011

Create sql file name_of_file.sqlIn name_of_file.sql file output to pipe 'mailx -s "SUBJECT"  mail_recepient' select * from table;Create a unix script name  "whatever&q...

Kalyan

• Oct 18th, 2005

Use DBMS_JOB for scheduling a cron job and DBMS_MAIL to send the results throught email.

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Tushar

• May 9th, 2007

Use Export and Import tools for backups and restore resp.you can use exp and imp as well

shuaib

• Nov 11th, 2005

U can backup the sql files through backup utilities or some backup command in sql . SAP is ERP software for the organization to integrate the software .

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naveen_vangapalli1

• May 26th, 2007

The select statement goes to oracle server and the server responds

shashi

• Oct 25th, 2005

First it will look into the System Global Area (SGA) weather the query is been exectued earlier.If it exist, it would retrive the same output present in memory.If not the query we typed...

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gunjan28

 Profile Answers by gunjan28 Questions by gunjan28

• Nov 11th, 2009

When using a count(distinct) it is better to use self-joinExp- in employees table to get manager name and total employees including manager querry will be-id first_name last_name m...

Sujatha

• Aug 1st, 2006

Hi All,Instead of this we can use GROUP BY Clause with HAVING condition.For ex,Select count(*),lastname from tblUsers group by lastname having count(*)>1This query return the duplicated lastnames values in the lastname column from tblUsers table.

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Please give some sub-query examples based on correlated sub-query and nested

Pallavi g rao

 Profile Answers by Pallavi g rao Questions by Pallavi g rao

• Apr 21st, 2011

correlated:- outer query is executed first and result is sent to inner query for execution       select * from emp e1 where e1.basicsal=(selcte max(basicsal) from emp e2 ...

nandlalseth

 Profile Answers by nandlalseth Questions by nandlalseth

• Aug 14th, 2008

Correlated Sub Query:Select * from emp e where exists (select 1 from dept d where d.deptno?= e.deptno)Nested Sub Query:Select * from emp e where deptno in (select deptno from dept d)

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