Author: Anonymous

Everything that’s physically possible is also logically possible.

If someone experiences the external world a certain way, then the external world is that way.

If we can’t give a scientific explanation of a phenomenon, then that phenomenon must have a supernatural/paranormal explanation.

No deductive arguments are cogent.

Without the laws of thought, communication would be impossible.

Given two files A and B and each file include 3 pages (each page contains 4 entries only) as shown as the following: A: [[1,5, -6,2], [6,4,-10,3],[20,8,-12,7]] B: [[5,6,7,1], [-10,1,2,-3], [-8,11,-15,6]] Assume you have 3 buffer pages in the main memory.            Show the 2-way merge sort (sort each page separately in the first pass, and then merge in the subsequent passes) procedure for the given example.     2. Compute the I/O cost for this procedure (rounding the value up)

What is the information stored in a catalog of database (in which metadata is stored) ?

The first step in optimizing a query is

Consider the following relations:  Suppliers(sid: integer, sname: string, address: string) Parts(pid: integer, pname: string, color: string) Catalog(sid: integer, pid: integer, price: real) Write the following queries in SQL and translate each of them into two equivalent relational algebra:  a. Find the names of suppliers who supply all blue parts. b. Find the names and pids of parts that have a price less than 200 dollars So the deliverables should be two SQL statements and 4 relational algebras. For relational algebra, use the following notation:  Selection: 

You are hired to help the Lead Technical Analyst of the FBI Behavioral Unit in joining various tables and doing cross-references to help the FBI field agents to fight crimes. You are working up against an incredibly tight deadline because the suspects (the “unsub”) may strike again in 24 hours. The tables that you are working with are big, but not sorted or indexed. You need to implement a decent join algorithm.  Will you choose tuple-based nested-loop join, block-based nested-loop join, sort-merge join, or hash join? Please justify your answer, i.e., clearly explain why you think your choice is the best among these 4 options by discussing inputs, pseudocode, and complexity for the join algorithm you are choosing.