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Column partially determining accepted values of another column, should be somehow normalized?
I have a table that describes a set of properties (yes it's metadata, in this case there's a valid reason to have it in the database); among other things I tell the type of the data that can be ...
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1answer
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Configuration options for relational algebra evaluator “ra.jar”
I am participating in the Stanford Database Class, and there are some problem sets to be solved in "mathy" relational algebra syntax.
The course instructors demand from students to use this ...
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1answer
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What is the real-world purpose of an optional 1:1 relationship?
I know that one-to-one relationships can be used to split data into multiple tables for performance or security and that it is used to create a is-a-relationsship.
But aside from that things, what is ...
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0answers
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Transform XPath map into XML document using relational data
Background
Most modern databases have XML functions that can be used to extract data in an XML format. I want to avoid the task of manually calling XML functions to extract the data.
This problem ...
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0answers
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Closure of attributes definition clarification
A databases book I am using states [1]:
The closure of {A1, A2, ..., An} under the FD's in S is the set of attributes B such that every relation that satisfies all the FD's in set S also satisfies ...
