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What is Normalization | DBMS
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<p class=MsoNormal style='text-align:justify;background:white'><span
lang=EN-IN style='font-size:19.0pt;font-family:"Helvetica",sans-serif;
color:#610B38'>What is Normalization?</span></p>

<ul style='margin-top:0in' type=circle>
 <li class=MsoNormal style='color:black;margin-top:3.0pt;text-align:justify;
     line-height:18.75pt;background:white'><span lang=EN-IN style='font-size:
     12.0pt;font-family:"Segoe UI",sans-serif'>Normalization is the process of
     organizing the data in the database.</span></li>
 <li class=MsoNormal style='color:black;margin-top:3.0pt;text-align:justify;
     line-height:18.75pt;background:white'><span lang=EN-IN style='font-size:
     12.0pt;font-family:"Segoe UI",sans-serif'>Normalization is used to
     minimize the redundancy from a relation or set of relations. It is also
     used to eliminate undesirable characteristics like Insertion, Update, and
     Deletion Anomalies.</span></li>
 <li class=MsoNormal style='color:black;margin-top:3.0pt;text-align:justify;
     line-height:18.75pt;background:white'><span lang=EN-IN style='font-size:
     12.0pt;font-family:"Segoe UI",sans-serif'>Normalization divides the larger
     table into smaller and links them using relationships.</span></li>
 <li class=MsoNormal style='color:black;margin-top:3.0pt;text-align:justify;
     line-height:18.75pt;background:white'><span lang=EN-IN style='font-size:
     12.0pt;font-family:"Segoe UI",sans-serif'>The normal form is used to
     reduce redundancy from the database table.</span></li>
</ul>

<p class=MsoNormal style='text-align:justify;line-height:normal;background:
white'><span lang=EN-IN style='font-size:12.0pt;font-family:"Arial Rounded MT Bold",sans-serif;
color:red'>Why do we need Normalization?</span></p>

<p class=MsoNormal style='text-align:justify;line-height:normal;background:
white'><span lang=EN-IN style='font-size:12.0pt;font-family:"Segoe UI",sans-serif;
color:#333333'>The main reason for normalizing the relations is removing these
anomalies. Failure to eliminate anomalies leads to data redundancy and can
cause data integrity and other problems as the database grows. Normalization
consists of a series of guidelines that helps to guide you in creating a good
database structure.</span></p>

<p class=MsoNormal style='text-align:justify;line-height:normal;background:
white'><b><span lang=EN-IN style='font-size:12.0pt;font-family:"Segoe UI",sans-serif;
color:#333333'>Data modification anomalies can be categorized into three types:</span></b></p>

<ul style='margin-top:0in' type=circle>
 <li class=MsoNormal style='color:black;margin-top:3.0pt;text-align:justify;
     line-height:18.75pt;background:white'><b><span lang=EN-IN
     style='font-size:12.0pt;font-family:"Segoe UI",sans-serif'>Insertion
     Anomaly:</span></b><span lang=EN-IN style='font-size:12.0pt;font-family:
     "Segoe UI",sans-serif'>&nbsp;Insertion Anomaly refers to when one cannot
     insert a new tuple into a relationship due to lack of data.</span></li>
 <li class=MsoNormal style='color:black;margin-top:3.0pt;text-align:justify;
     line-height:18.75pt;background:white'><b><span lang=EN-IN
     style='font-size:12.0pt;font-family:"Segoe UI",sans-serif'>Deletion
     Anomaly:</span></b><span lang=EN-IN style='font-size:12.0pt;font-family:
     "Segoe UI",sans-serif'>&nbsp;The delete anomaly refers to the situation
     where the deletion of data results in the unintended loss of some other
     important data.</span></li>
 <li class=MsoNormal style='color:black;margin-top:3.0pt;text-align:justify;
     line-height:18.75pt;background:white'><b><span lang=EN-IN
     style='font-size:12.0pt;font-family:"Segoe UI",sans-serif'>Updatation
     Anomaly:</span></b><span lang=EN-IN style='font-size:12.0pt;font-family:
     "Segoe UI",sans-serif'>&nbsp;The update anomaly is when an update of a
     single data value requires multiple rows of data to be updated.</span></li>
</ul>

<p class=MsoNormal style='text-align:justify;line-height:15.6pt;background:
white'><span lang=EN-IN style='font-size:12.0pt;font-family:"Arial Rounded MT Bold",sans-serif;
color:#610B38'>Types of Normal Forms:</span></p>

<p class=MsoNormal style='text-align:justify;line-height:normal;background:
white'><span lang=EN-IN style='font-size:12.0pt;font-family:"Arial Rounded MT Bold",sans-serif;
color:#333333'>Normalization works through a series of stages called Normal
forms. The normal forms apply to individual relations. The relation is said to
be in particular normal form if it satisfies constraints.</span></p>

<p class=MsoNormal style='text-align:justify;line-height:normal;background:
white'><b><span lang=EN-IN style='font-size:12.0pt;font-family:"Arial Rounded MT Bold",sans-serif;
color:#333333'>Following are the various types of Normal forms:</span></b></p>

<p class=MsoNormal style='margin-bottom:0in;line-height:normal'><span
lang=EN-IN style='font-size:12.0pt;font-family:"Arial Rounded MT Bold",sans-serif'>&nbsp;</span></p>

<table class=MsoNormalTable border=1 cellspacing=0 cellpadding=0 width=693
 style='width:519.5pt;background:white;border-collapse:collapse;border:none'>
 <tr>
  <td valign=top style='border-top:solid #C7CCBE 1.0pt;border-left:solid #C7CCBE 1.0pt;
  border-bottom:none;border-right:none;background:#C7CCBE;padding:9.0pt 9.0pt 9.0pt 9.0pt'>
  <p class=MsoNormal style='margin-bottom:0in;line-height:normal'><b><span
  lang=EN-IN style='font-size:12.0pt;font-family:"Arial Rounded MT Bold",sans-serif;
  color:black'>Normal Form</span></b></p>
  </td>
  <td valign=top style='border-top:solid #C7CCBE 1.0pt;border-left:none;
  border-bottom:none;border-right:solid #C7CCBE 1.0pt;background:#C7CCBE;
  padding:9.0pt 9.0pt 9.0pt 9.0pt'>
  <p class=MsoNormal style='margin-bottom:0in;line-height:normal'><b><span
  lang=EN-IN style='font-size:12.0pt;font-family:"Arial Rounded MT Bold",sans-serif;
  color:black'>Description</span></b></p>
  </td>
 </tr>
 <tr>
  <td valign=top style='border:solid #C7CCBE 1.0pt;padding:6.0pt 6.0pt 6.0pt 6.0pt'>
  <p class=MsoNormal style='margin-bottom:0in;text-align:justify;line-height:
  normal'><span lang=EN-IN style='color:black'><a
  href="https://www.javatpoint.com/dbms-first-normal-form"><span
  style='font-size:12.0pt;font-family:"Arial Rounded MT Bold",sans-serif;
  color:green;text-decoration:none'>1NF</span></a></span></p>
  </td>
  <td valign=top style='border:solid #C7CCBE 1.0pt;border-left:none;padding:
  6.0pt 6.0pt 6.0pt 6.0pt'>
  <p class=MsoNormal style='margin-bottom:0in;text-align:justify;line-height:
  normal'><span lang=EN-IN style='font-size:12.0pt;font-family:"Arial Rounded MT Bold",sans-serif;
  color:#333333'>A relation is in 1NF if it contains an atomic value.</span></p>
  </td>
 </tr>
 <tr>
  <td valign=top style='border:solid #C7CCBE 1.0pt;border-top:none;background:
  #EFF1EB;padding:6.0pt 6.0pt 6.0pt 6.0pt'>
  <p class=MsoNormal style='margin-bottom:0in;text-align:justify;line-height:
  normal'><span lang=EN-IN style='color:black'><a
  href="https://www.javatpoint.com/dbms-second-normal-form"><span
  style='font-size:12.0pt;font-family:"Arial Rounded MT Bold",sans-serif;
  color:green;text-decoration:none'>2NF</span></a></span></p>
  </td>
  <td valign=top style='border-top:none;border-left:none;border-bottom:solid #C7CCBE 1.0pt;
  border-right:solid #C7CCBE 1.0pt;background:#EFF1EB;padding:6.0pt 6.0pt 6.0pt 6.0pt'>
  <p class=MsoNormal style='margin-bottom:0in;text-align:justify;line-height:
  normal'><span lang=EN-IN style='font-size:12.0pt;font-family:"Arial Rounded MT Bold",sans-serif;
  color:#333333'>A relation will be in 2NF if it is in 1NF and all non-key
  attributes are fully functional dependent on the primary key.</span></p>
  </td>
 </tr>
 <tr>
  <td valign=top style='border:solid #C7CCBE 1.0pt;border-top:none;padding:
  6.0pt 6.0pt 6.0pt 6.0pt'>
  <p class=MsoNormal style='margin-bottom:0in;text-align:justify;line-height:
  normal'><span lang=EN-IN style='color:black'><a
  href="https://www.javatpoint.com/dbms-third-normal-form"><span
  style='font-size:12.0pt;font-family:"Arial Rounded MT Bold",sans-serif;
  color:green;text-decoration:none'>3NF</span></a></span></p>
  </td>
  <td valign=top style='border-top:none;border-left:none;border-bottom:solid #C7CCBE 1.0pt;
  border-right:solid #C7CCBE 1.0pt;padding:6.0pt 6.0pt 6.0pt 6.0pt'>
  <p class=MsoNormal style='margin-bottom:0in;text-align:justify;line-height:
  normal'><span lang=EN-IN style='font-size:12.0pt;font-family:"Arial Rounded MT Bold",sans-serif;
  color:#333333'>A relation will be in 3NF if it is in 2NF and no transition
  dependency exists.</span></p>
  </td>
 </tr>
 <tr>
  <td valign=top style='border:solid #C7CCBE 1.0pt;border-top:none;background:
  #EFF1EB;padding:6.0pt 6.0pt 6.0pt 6.0pt'>
  <p class=MsoNormal style='margin-bottom:0in;text-align:justify;line-height:
  normal'><span lang=EN-IN style='font-size:12.0pt;font-family:"Arial Rounded MT Bold",sans-serif;
  color:#333333'>BCNF</span></p>
  </td>
  <td valign=top style='border-top:none;border-left:none;border-bottom:solid #C7CCBE 1.0pt;
  border-right:solid #C7CCBE 1.0pt;background:#EFF1EB;padding:6.0pt 6.0pt 6.0pt 6.0pt'>
  <p class=MsoNormal style='margin-bottom:0in;text-align:justify;line-height:
  normal'><span lang=EN-IN style='font-size:12.0pt;font-family:"Arial Rounded MT Bold",sans-serif;
  color:#333333'>A stronger definition of 3NF is known as Boyce Codd's normal
  form.</span></p>
  </td>
 </tr>
 <tr>
  <td valign=top style='border:solid #C7CCBE 1.0pt;border-top:none;padding:
  6.0pt 6.0pt 6.0pt 6.0pt'>
  <p class=MsoNormal style='margin-bottom:0in;text-align:justify;line-height:
  normal'><span lang=EN-IN style='color:black'><a
  href="https://www.javatpoint.com/dbms-forth-normal-form"><span
  style='font-size:12.0pt;font-family:"Arial Rounded MT Bold",sans-serif;
  color:green;text-decoration:none'>4NF</span></a></span></p>
  </td>
  <td valign=top style='border-top:none;border-left:none;border-bottom:solid #C7CCBE 1.0pt;
  border-right:solid #C7CCBE 1.0pt;padding:6.0pt 6.0pt 6.0pt 6.0pt'>
  <p class=MsoNormal style='margin-bottom:0in;text-align:justify;line-height:
  normal'><span lang=EN-IN style='font-size:12.0pt;font-family:"Arial Rounded MT Bold",sans-serif;
  color:#333333'>A relation will be in 4NF if it is in Boyce Codd's normal form
  and has no multi-valued dependency.</span></p>
  </td>
 </tr>
 <tr>
  <td valign=top style='border:solid #C7CCBE 1.0pt;border-top:none;background:
  #EFF1EB;padding:6.0pt 6.0pt 6.0pt 6.0pt'>
  <p class=MsoNormal style='margin-bottom:0in;text-align:justify;line-height:
  normal'><span lang=EN-IN style='color:black'><a
  href="https://www.javatpoint.com/dbms-fifth-normal-form"><span
  style='font-size:12.0pt;font-family:"Arial Rounded MT Bold",sans-serif;
  color:green;text-decoration:none'>5NF</span></a></span></p>
  </td>
  <td valign=top style='border-top:none;border-left:none;border-bottom:solid #C7CCBE 1.0pt;
  border-right:solid #C7CCBE 1.0pt;background:#EFF1EB;padding:6.0pt 6.0pt 6.0pt 6.0pt'>
  <p class=MsoNormal style='margin-bottom:0in;text-align:justify;line-height:
  normal'><span lang=EN-IN style='font-size:12.0pt;font-family:"Arial Rounded MT Bold",sans-serif;
  color:#333333'>A relation is in 5NF. If it is in 4NF and does not contain any
  join dependency, joining should be lossless.</span></p>
  </td>
 </tr>
</table>

<p class=MsoNormal style='text-align:justify;line-height:15.6pt;background:
white'><span lang=EN-IN style='font-size:12.0pt;font-family:"Arial Rounded MT Bold",sans-serif;
color:#610B38'>Advantages of Normalization</span></p>

<ul style='margin-top:0in' type=circle>
 <li class=MsoNormal style='color:black;margin-top:3.0pt;text-align:justify;
     line-height:18.75pt;background:white'><span lang=EN-IN style='font-size:
     12.0pt;font-family:"Arial Rounded MT Bold",sans-serif'>Normalization helps
     to minimize data redundancy.</span></li>
 <li class=MsoNormal style='color:black;margin-top:3.0pt;text-align:justify;
     line-height:18.75pt;background:white'><span lang=EN-IN style='font-size:
     12.0pt;font-family:"Arial Rounded MT Bold",sans-serif'>Greater overall
     database organization.</span></li>
 <li class=MsoNormal style='color:black;margin-top:3.0pt;text-align:justify;
     line-height:18.75pt;background:white'><span lang=EN-IN style='font-size:
     12.0pt;font-family:"Arial Rounded MT Bold",sans-serif'>Data consistency
     within the database.</span></li>
 <li class=MsoNormal style='color:black;margin-top:3.0pt;text-align:justify;
     line-height:18.75pt;background:white'><span lang=EN-IN style='font-size:
     12.0pt;font-family:"Arial Rounded MT Bold",sans-serif'>Much more flexible
     database design.</span></li>
 <li class=MsoNormal style='color:black;margin-top:3.0pt;text-align:justify;
     line-height:18.75pt;background:white'><span lang=EN-IN style='font-size:
     12.0pt;font-family:"Arial Rounded MT Bold",sans-serif'>Enforces the
     concept of relational integrity.</span></li>
</ul>

<p class=MsoNormal style='text-align:justify;line-height:15.6pt;background:
white'><span lang=EN-IN style='font-size:12.0pt;font-family:"Arial Rounded MT Bold",sans-serif;
color:#610B38'>Disadvantages of Normalization</span></p>

<ul style='margin-top:0in' type=circle>
 <li class=MsoNormal style='color:black;margin-top:3.0pt;text-align:justify;
     line-height:18.75pt;background:white'><span lang=EN-IN style='font-size:
     12.0pt;font-family:"Arial Rounded MT Bold",sans-serif'>You cannot start
     building the database before knowing what the user needs.</span></li>
 <li class=MsoNormal style='color:black;margin-top:3.0pt;text-align:justify;
     line-height:18.75pt;background:white'><span lang=EN-IN style='font-size:
     12.0pt;font-family:"Arial Rounded MT Bold",sans-serif'>The performance
     degrades when normalizing the relations to higher normal forms, i.e., 4NF,
     5NF.</span></li>
 <li class=MsoNormal style='color:black;margin-top:3.0pt;text-align:justify;
     line-height:18.75pt;background:white'><span lang=EN-IN style='font-size:
     12.0pt;font-family:"Arial Rounded MT Bold",sans-serif'>It is very
     time-consuming and difficult to normalize relations of a higher degree.</span></li>
 <li class=MsoNormal style='color:black;margin-top:3.0pt;text-align:justify;
     line-height:18.75pt;background:white'><span lang=EN-IN style='font-size:
     12.0pt;font-family:"Arial Rounded MT Bold",sans-serif'>Careless
     decomposition may lead to a bad database design, leading to serious
     problems.</span></li>
</ul>

<p class=MsoNormal><span lang=EN-IN style='font-size:12.0pt;line-height:115%;
font-family:"Arial Rounded MT Bold",sans-serif'>&nbsp;</span></p>

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