Discussion about normal forms in SQL

[ronitreddy]

[quote author=meghana9 link=topic=219396.msg2702810#msg2702810 date=1312299614]
NOrmals forms aipoina tarvatha ..we can discuss Performance tuning... bcos Normalisation ardhamithe then denormalisation ardhamavuthundhi which is a performance tuning
[/quote]

wakey.. S%Hi

[Virat Kohli]

[quote author=jamesbond link=topic=219396.msg2702835#msg2702835 date=1312299824]
namma Bengalooru huduga :P
[/quote] !q# !q# !q# !q# !q# !q# !q#

[charygaru]

[quote author=galigannarao link=topic=219396.msg2702812#msg2702812 date=1312299624]
Normalization

A logical design method which minimizes data redundancy and reduces design flaws.

Consists of applying various “normal” forms to the database design.
The normal forms break down large tables into smaller subsets.

[/quote]

ante data ni database lo pette mundu aa database ni ela create cheyyalo use chese paddathi aa idi ?? i never came across these terms anduke aduguthunna

[Ranga_The_Donga]

[quote author=jamesbond link=topic=219396.msg2702831#msg2702831 date=1312299789]
yeah ade anukuntanna.... I never came across these

Probably database developer use chestaaremo... memedo chinna analyst lam  @3$%
[/quote]

kani me analystlu requirements for a prj ela develop chestaru ba....... sCo_^Y sCo_^Y sCo_^Y

[charygaru]

[quote author=jamesbond link=topic=219396.msg2702835#msg2702835 date=1312299824]
namma Bengalooru huduga :P
[/quote]

magaaaaa [img]http://www.gifsoup.com/view1/2119144/raga-o.gif[/img]

[galigannarao]

Table : Employee (1NF)
emp_no name dept_no dept_name skills
1 Kevin Jacobs 201 R&D C
1 Kevin Jacobs 201 R&D Perl
1 Kevin Jacobs 201 R&D Java
2 Barbara Jones 224 IT Linux
2 Barbara Jones 224 IT Mac
3 Jake Rivera 201 R&D DB2
3 Jake Rivera 201 R&D Oracle
3 Jake Rivera 201 R&D Java


Name, dept_no, and dept_name are functionally dependent on emp_no.  (emp_no -> name, dept_no, dept_name)

Skills is not functionally dependent on emp_no since it is not unique to each emp_no.

Table: Employee (2NF)
emp_no name dept_no dept_name skills
1 Kevin Jacobs 201 R&D C, Perl, Java
2 Barbara Jones 224 IT Linux, Mac
3 Jake Rivera 201 R&D DB2, Oracle, Java

Table: Skills (2NF)
emp_no skills
1 C
1 Perl
1 Java
2 Linux
2 Mac
3 DB2
3 Oracle
3 Java

[ladysfinger]

akkada job chesevaadivaa.  [quote author=jamesbond link=topic=219396.msg2702835#msg2702835 date=1312299824]
namma Bengalooru huduga :P
[/quote]

[ronitreddy]

[quote author=jamesbond link=topic=219396.msg2702835#msg2702835 date=1312299824]
namma Bengalooru huduga :P
[/quote]

Hegidiya  H&*() H&*()

[Virat Kohli]

[quote author=charygaru link=topic=219396.msg2702841#msg2702841 date=1312299894]
ante data ni database lo pette mundu aa database ni ela create cheyyalo use chese paddathi aa idi ?? i never came across these terms anduke aduguthunna
[/quote]

exactly  H&*() H&*() H&*()  ela create cheste efficient ga vuntado ani decide cheskune padhati anukunta  s%H# s%H# s%H#

[charygaru]

[quote author=ronitreddy link=topic=219396.msg2702851#msg2702851 date=1312299960]
Hegidiya  H&*() H&*()
[/quote]

chennagid iya  sCo_^Y sCo_^Y sCo_^Y sCo_^Y

[galigannarao]

[quote author=charygaru link=topic=219396.msg2702841#msg2702841 date=1312299894]
ante data ni database lo pette mundu aa database ni ela create cheyyalo use chese paddathi aa idi ?? i never came across these terms anduke aduguthunna
[/quote]avnu baa these are all the basic steps need to be followed while creating a database H&*()

[jamesbond]

[quote author=Virat Kohli link=topic=219396.msg2702838#msg2702838 date=1312299855]
!q# !q# !q# !q# !q# !q# !q#
[/quote]
10gay bhe  ^G#W

[Ranga_The_Donga]

[quote author=Virat Kohli link=topic=219396.msg2702854#msg2702854 date=1312299973]
exactly  H&*() H&*() H&*()  ela create cheste efficient ga vuntado ani decide cheskune padhati anukunta  s%H# s%H# s%H#
[/quote]

@gr33d database design....

[galigannarao]

Data Intergrity(continuous to my previous quote)

Insert Anomaly - adding null values.  eg, inserting a new department does not require the primary key of emp_no to be added.
Update Anomaly - multiple updates for a single name change, causes performance degradation.  eg, changing IT dept_name to IS
Delete Anomaly - deleting wanted information.  eg, deleting the IT department removes employee Barbara Jones from the database

[Virat Kohli]

[quote author=galigannarao link=topic=219396.msg2702848#msg2702848 date=1312299943]
Table : Employee (1NF)
emp_no name dept_no dept_name skills
1 Kevin Jacobs 201 R&D C
1 Kevin Jacobs 201 R&D Perl
1 Kevin Jacobs 201 R&D Java
2 Barbara Jones 224 IT Linux
2 Barbara Jones 224 IT Mac
3 Jake Rivera 201 R&D DB2
3 Jake Rivera 201 R&D Oracle
3 Jake Rivera 201 R&D Java


Name, dept_no, and dept_name are functionally dependent on emp_no.  (emp_no -> name, dept_no, dept_name)

Skills is not functionally dependent on emp_no since it is not unique to each emp_no.

Table: Employee (2NF)
emp_no name dept_no dept_name skills
1 Kevin Jacobs 201 R&D C, Perl, Java
2 Barbara Jones 224 IT Linux, Mac
3 Jake Rivera 201 R&D DB2, Oracle, Java

Table: Skills (2NF)
emp_no skills
1 C
1 Perl
1 Java
2 Linux
2 Mac
3 DB2
3 Oracle
3 Java
[/quote] thankyou thankyou thankyou thankyou thankyou CITI_$D# CITI_$D# CITI_$D# CITI_$D# CITI_$D#