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@stepbystep001

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The problem of deletion anomalies is related to the second insertion anomaly situation just discussed.
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.........is the process of organizing data in a database
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Organization
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Normalization
Database Normalization is a database schema design technique, by which an existing schema is modified to maximize redundancy and dependency of data
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Normalization split a … table into … tables and define relationships between them to increases
the clarity in organizing data.
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large - smaller
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Normalization … clarity in organizing data in Databases
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increases
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Normalization of a Database is achieved by following a set of rules called …. in creating the database
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forms
The constraint is that, for any two tuples t1 and t2 in r that have: t1[X] = t2[X], they must also have
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t1[X] = t2[Y]
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t1[Y] = t2[Y]
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t1[Y] = t2[X]
If X→Y in R, this says Y→X in R
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We also say that there is a functional dependency from X to Y, or that Y is functionally dependent on X
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Y → X
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X → Y
The normal form of a relation refers to the....normal form condition that it meets, and hence indicates the degree to which it has been normalized.
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A series of normal form tests can be carried out on individual relation schemas so that the relational database can be normalized to any desired degree.
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This means that the values of the Y component of a tuple in r depend on, or are determined by, the values of the X component
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Y → X
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X → Y
The database normalization process is divided into
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(1NF)
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(2NF)
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(3NF)
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(4NF)
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(5NF)
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(BCNF)
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All of the above
المحاضره التاسعه
First Normal Form [1NF] Every column of a table should contain only atomic values. An atomic value is a value that cannot be divided further.
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database is said to be in first normal form if it satisfies the following conditions:
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contain only atomic values
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contain repeating columns.
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1NF should not contain repeating columns.
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Second Normal Form (2NF) is based on the concept of
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partial dependency
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full functional dependency.
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Second Normal Form applies to relations with Only Single keys
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Second Normal Form applies to relations with composite keys, that is, relations with a primary key composed of two or more attributes.
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