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cs-236:relational-database [2017/10/27 00:07]
kylej13 [FAQ]
cs-236:relational-database [2018/10/18 21:53] (current)
pdiddy [Part 2: RDBMS-based Interpreter]
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 * At least 4 of the 10 tests must mimic a datalog query in that they use a sequence of select, project, and rename to answer the query (as explained below in the FAQ). * At least 4 of the 10 tests must mimic a datalog query in that they use a sequence of select, project, and rename to answer the query (as explained below in the FAQ).
 * The tests must be testing either a select, project, rename, or a query; they may '''​not'''​ test if the relation you create is structured properly (i.e. proper sorting, no duplicates, etc.; while these things are important, they are not what should be tested). * The tests must be testing either a select, project, rename, or a query; they may '''​not'''​ test if the relation you create is structured properly (i.e. proper sorting, no duplicates, etc.; while these things are important, they are not what should be tested).
 +** Both types of selects must be implemented.
 * The tests must be documented and justified: what does the test accomplish? * The tests must be documented and justified: what does the test accomplish?
 ** Each test must be marked with comments explaining what operation is being performed and why. ** Each test must be marked with comments explaining what operation is being performed and why.
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 * '''​Output''':​ see the [[datalog-parser#​Output Specifications|output specifications]] and [[datalog-parser#​Examples | examples]] * '''​Output''':​ see the [[datalog-parser#​Output Specifications|output specifications]] and [[datalog-parser#​Examples | examples]]
  
-Part 2 is scored on a set of 10 private tests at submission. ​+Part 2 is scored on a set of private tests at submission. ​
 ==Examples== ==Examples==
  
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 # It can find all the tuples that have the same value in two columns (doesn'​t matter what that value is, as long as the two columns both have it). # It can find all the tuples that have the same value in two columns (doesn'​t matter what that value is, as long as the two columns both have it).
 The schema stays the same. The schema stays the same.
 +
 +'''​If the select operation finds when two columns have the same value, should it also find when two columns have different values?'''​
 +
 +No. If a query has two different variables in it, that does not mean the select must find tuples with different values in those columns. Consider the last query of the first example:
 +
 +<​code>​
 +SK(A,B)? Yes(3)
 +  A='​a',​ B='​c'​
 +  A='​b',​ B='​b'​
 +  A='​b',​ B='​c'​
 +</​code>​
 +
 +While A and B are different variables, the query still includes when the values are the same in the tuple (the second result where both A and B equal '​b'​).
  
 '''​What does the project operation do?'''​ '''​What does the project operation do?'''​
cs-236/relational-database.1509062859.txt.gz ยท Last modified: 2017/10/27 00:07 by kylej13
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