Outer join Query

Question

How is the maximum number of tuples for left outer join m*n. Can anyone please provide an example?

Comments

All the tuples which are present in left side of table are present in the output

therefore m * n

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How m*n ? If left side table contains m tuples and right contains n then if only left side tuples come there should be m tuples. Can you please give an example I can't seem to wrap my head around it.

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check it !

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in left outer join we basically have A xA \cap B) \cup A. IF there is nothing returned by the intersection then the output will produce m records. If for every record in A we have a record in B then number of tuples will be max(m,n).$

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Thank you so much for the example! I have been at it for hours!

Answer 1

All the tuples which are there on the left-hand side will be present in the output as well.

Hence, the solution will be m*n, very simple, though Magma explained it very clearly with the sample diagram.