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+CS122 Assignment 4 - Join Optimization - Design Document
+========================================================
+
+Fill in answers for all questions based on your team's work on Assignment 4.
+
+A: Refactoring Your Planner
+----------------------------
+
+A1. What did you name your planner base-class? Briefly describe what
+ functionality you migrated into this class.
+
+A2. Was there any functionality that is common to both your SimplePlanner
+ and your CostBasedJoinPlanner that you left duplicated in the
+ subclasses? If so, explain your rationale for each part of the
+ duplicated functionality.
+
+B: Generating Optimal Joins
+----------------------------
+
+B1. Briefly describe how you generate an "optimal" access to a base table.
+
+B2. Briefly describe how you decide when it is acceptable to push
+ conjuncts down through an outer join.
+
+B3. The planner in this assignment is still somewhat limited; for example,
+ we can't push conjuncts down into subqueries. Using the stores schema,
+ write an example SQL query that includes a subquery, where it would be
+ beneficial to push a conjunct down into the subquery. (Your planner
+ obviously doesn't need to perform this optimization.)
+
+B4. Enumerate the situations where you call prepare() on plans being
+ generated. Since this operation is somewhat expensive, do you
+ see any ways to reduce the number of times you call prepare() in
+ your implementation?
+
+B5. Given a schema t1(a, c1), t2(a, c2), t3(a, c3), and this SQL query:
+ SELECT * FROM t1 JOIN t2 ON t1.a = t2.a JOIN t3 ON t2.a = t3.a;
+
+ Assume that we are using the simple cost-based join planning strategy
+ described in this assignment. What issue arises when the planner
+ considers joining the pair of tables t1 and t3 first? What can be done
+ to resolve this problem? (Your planner does not have to implement
+ this functionality!)
+
+B6. Is it possible to end up with unused conjuncts (from the WHERE and ON
+ clauses) after planning joins? Briefly explain why or why not.
+
+C: Costing SQL Queries
+-----------------------
+
+After you have loaded the stores-28K.sql data and have analyzed all of
+the tables in that schema, run the following explain operations and paste
+the output from your planner (excluding debug output!).
+
+If there is anything unusual or non-obvious about your output, feel free
+to write explanatory notes after your output.
+
+C1. EXPLAIN SELECT * FROM cities WHERE population > 5000000;
+
+C2. EXPLAIN SELECT store_id FROM stores, cities
WHERE stores.city_id = cities.city_id AND
+ cities.population > 1000000;
+
+C3. EXPLAIN SELECT store_id FROM stores JOIN
(SELECT city_id FROM cities
WHERE population > 1000000) AS big_cities
ON stores.city_id = big_cities.city_id;
+
+C4. EXPLAIN SELECT store_id, property_costs
FROM stores, cities, states
WHERE stores.city_id = cities.city_id AND
+ cities.state_id = states.state_id AND
state_name = 'Oregon' AND property_costs > 500000;
+
+D: Extra Credit [OPTIONAL]
+---------------------------
+
+If you implemented any extra-credit tasks for this assignment, describe
+them here. The description should be like this, with stuff in "<>" replaced.
+(The value i starts at 1 and increments...)
+
+D<i>: <one-line description>
+
+ <brief summary of what you did, including the specific classes that
+ we should look at for your implementation>
+
+ <brief summary of test-cases that demonstrate/exercise your extra work>
+
+E: Feedback [OPTIONAL]
+-----------------------
+
+WE NEED YOUR FEEDBACK! Thoughtful and constructive input will help us to
+improve future versions of the course. These questions are OPTIONAL, and
+your answers will not affect your grade in any way (including if you hate
+everything about the assignment and databases in general, or Donnie and/or
+the TAs in particular). Feel free to answer as many or as few of them as
+you wish.
+
+E1. What parts of the assignment were most time-consuming? Why?
+
+E2. Did you find any parts of the assignment particularly instructive?
+ Correspondingly, did any parts feel like unnecessary busy-work?
+
+E3. Did you particularly enjoy any parts of the assignment? Were there
+ any parts that you particularly disliked?
+
+E4. Were there any critical details that you wish had been provided with the
+ assignment, that we should consider including in subsequent versions of
+ the assignment?
+
+E5. Do you have any other suggestions for how future versions of the
+ assignment can be improved?
+
diff --git a/doc/lab4info.txt b/doc/lab4info.txt
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+CS122 Assignment 4 - Join Optimization
+======================================
+
+Please completely fill out this document so that we know who participated on
+the assignment, any late extensions received, and how much time the assignment
+took for your team. Thank you!
+
+L1. List your team name and the people who worked on this assignment.
+
+ <team name>
+
+ <name>
+ <name>
+ ...
+
+L2. Specify the tag and commit-hash of the Git commit you are submitting for
+ your assignment. (You can list the hashes of all tags with the command
+ "git show-ref --tags".)
+
+ Tag: <tag>
+ Commit hash: <hash>
+
+L3. Specify how many late tokens you are applying to this assignment, if any.
+ Similarly, if your team received an extension from Donnie then please
+ indicate how many days extension you received. You may leave this blank
+ if it is not relevant to this submission.
+
+ <tokens / extension>
+
+L4. For each teammate, briefly describe what parts of the assignment each
+ teammate focused on, along with the total hours spent on the assignment.
+
+