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How do you determine the base table?

My question is in relation to database theory.

If I am given a set of tables, is there a way to determine the base table just by looking at them?

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user559142 Avatar asked Apr 21 '11 18:04

user559142


2 Answers

It is a tenet of the relational model that there is no unnecessary distinction between a Base Table (Base Relation) and a Derived one (aka virtual relation or "view"). Both types have attributes, keys and all the other features you would expect of relations and both can be used in just the same ways. As a practical matter of implementation it is necessary that the DBMS software provide some means to differentiate them but logically speaking they are the same.

The principle that base and derived relations are similar in this way is sometimes called the Principle of Interchangeability.

Actually, I'm surprised there is so much puzzlement here about your question and surprised that your question is downvoted. Base table / relation is a very common term in relational database theory and in the SQL standard. Your question seems perfectly concise and in order to me.

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nvogel Avatar answered Sep 18 '22 22:09

nvogel


Disclaimer: I never heard of a "base table" before now

After some googling, the only instances where anyone is talking about "Base Tables", seems to be when describing the physical tables a view depends on.

Based on that, I would say all tables are base tables, with the possible exception of temporary tables.

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mikerobi Avatar answered Sep 16 '22 22:09

mikerobi