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HW3 Question 3b how pushing parts of the query down the tree changes the query

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Hi all,

In HW3 question 3 part b, we are asked to describe a transformation on the query that would improve its evalutation but in the solution it seems that the transformation suggested are made on the relational algebra tree and not on the SQL query itself as in part a of the same question, are we to assume, when asked to modify a query, that we change both its SQL and its relational algebra tree?

Thanks

asked Feb 4, 2018 by uribracha (3,110 points)
aren't they equivalent?
I'm not sure, maybe they are but a single query can have multiple relational algebra trees.
I can't answer questions without references , but I welcome other students to do so! good luck :-)
You need a reference to the homework you gave us?
Sorry, as we said so many times, I can't solve your hw/exams questions. Ask me technical stuff that you don't understand. Otherwise as you know, you need to schedule an office hour

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