Questions from Database Systems

Q: What characteristics of an application make it easy to scale the application

What characteristics of an application make it easy to scale the application by using a key-value store, and what characteristics rule out deployment on key-value stores?

Q: Give an example where the read one, write all available approach

Give an example where the read one, write all available approach leads to an erroneous state.

Q: In the majority protocol, what should the reader do if it

In the majority protocol, what should the reader do if it finds different values from different copies, to (a) decide what is the correct value, and (b) to bring the copies back to consistency? If the re...

Q: If we apply a distributed version of the multiple-granularity protocol

If we apply a distributed version of the multiple-granularity protocol of Chapter 18 to a distributed database, the site responsible for the root of the DAG may become a bottleneck. Suppose we modify...

Q: Discuss the advantages and disadvantages of the two methods that we presented

Discuss the advantages and disadvantages of the two methods that we presented in Section 23.3.4 for generating globally unique timestamps.

Q: Spanner provides read-only transactions a snapshot view of data,

Spanner provides read-only transactions a snapshot view of data, using multi- version two-phase locking. a. In the centralized multi-version 2PL scheme, read-only transactions never wait. But in Spann...

Q: Markel trees can be made short and fat (like B+-

Markel trees can be made short and fat (like B+-trees) or thin and tall (like binary search trees). Which option would be better if you are comparing data across two sites that are geographically sepa...

Q: Why is the notion of term important when an election is used

Why is the notion of term important when an election is used to choose a coordinator? What are the analogies between elections with terms and elections used in a democracy?

Q: Write the following queries in SQL, using the university schema.

Write the following queries in SQL, using the university schema. A. Find the ID and name of each student who has taken at least one Comp. Sci. course; make sure there are no duplicate names in the res...

Q: Web sites that want to get some publicity can join a web

Web sites that want to get some publicity can join a web ring, where they create links to other sites in the ring in exchange for other sites in the ring creating links to their site. What is the effec...