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Attribute
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Value
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Name
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Create Column
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Description
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None
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Function
|
None
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Aim
|
Allow a data engineer (user) to append an empty column to the end of the dataset
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Context
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This is used when a user requires a new column to be appended to the dataset to be filled with values in subsequent operations to fulfil requirements of the analysis for which the dataset is to serve as input.
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Rationale
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adding a column is used when certain values are implicit in the data and are required for subsequent operations or end-goal analysis the dataset is being prepared for.
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Mechanisim
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Increase dataset dimension horizontally by adding a column of blank values to be filled in subsequent operations. This can be done by exploring the facilities found in GUI-based tools and programming language functions.
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Formalisim
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α(R, x)={(a1,...,an,x) | (a1,...,an) ∈ R}, Where: R is a relation with n columns. x is a value representing the new column's name. (Raman, V and Hellerstein, J 2001)
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|
Relational Algebra (RA)
|
Similar to RA operation
Attribute Extension (ε)/Generalized Projection
|
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Type
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Atomic
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|
Class
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Unary
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|
Transformation_category
|
1:1
|
|
Inputs
|
| Inputs | Number of input datasets |
|---|
| Input dataset, new column name | 1 |
|
|
Outputs
|
| Outputs | Number of output datasets |
|---|
| dataset | 1 |
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|
Used in stage(s)
|
Structuring1
|