Lecture - 16 Query Processing and Optimization - III

[tnegi42]

where is lecture 17 to lecture 23 of Dr.S.Srinath

anybody help please

and thanks in advance

[mkaul78]

At 29:57, you say that all possible Manager tuples are joined with all possible Dept tuples, this to me sounds like a Cartesian Cross product that would be indicated by a "X" in the internal node above Manager and Dept leaf nodes. So doesn't the join shown in the diagram, (maybe a Nested Loop Join) drastically reduce this number already? Just wondering if you can clarify.

[mkaul78]

Can you give me an example when "selection pushing" is not a good idea?

[mkaul78]

@mkaul78 ok 33:51 answers my question: It says there is an exception, because of view expansion that we want the select to move up beyond the view. Ok thanks!