Questions from Database Systems

Q: What are the factors that can work against linear scale up in

What are the factors that can work against linear scale up in a transaction processing system? Which of the factors are likely to be the most important in each of the following architectures: shared-m...

Q: Memory systems today are divided into multiple modules, each of which

Memory systems today are divided into multiple modules, each of which can be serving a separate request at a given time, in contrast to earlier architectures where there was a single interface to memo...

Q: Assume we have data items d1, d2, d n with

Assume we have data items d1, d2, d n with each di protected by a lock stored in memory location Mi. a. Describe the implementation of lock-X (di) and unlock (di) via the use of the test-and-set instr...

Q: In a shared-nothing system data access from a remote node

In a shared-nothing system data access from a remote node can be done by remote procedure calls, or by sending messages. But remote direct memory access (RDMA) provides a much faster mechanism for suc...

Q: Using the university schema, write an SQL query to find the

Using the university schema, write an SQL query to find the number of students in each section. The result columns should appear in the order “coursed, secede, year, semester, numb”. You do not need to...

Q: Suppose that a major database vendor offers its database system (e

Suppose that a major database vendor offers its database system (e.g., Oracle, SQL Server DB2) as a cloud service. Where would this fit among the cloud- service models? Why?

Q: For each of the three partitioning techniques, namely, round-

For each of the three partitioning techniques, namely, round-robin, hash partitioning, and range partitioning, give an example of a query for which that partitioning technique would provide the fastes...

Q: Consider the E-R diagram in Figure 8.9,

Consider the E-R diagram in Figure 8.9, which contains specializations, using subtypes and sub tables. a. Give an SQL schema definition of the E-R diagram. b. Give an SQL query to find the names of all...

Q: What factors could result in skew when a relation is partitioned on

What factors could result in skew when a relation is partitioned on one of its attributes by: a. Hash partitioning? b. Range partitioning? In each case, what can be done to reduce the skew?

Q: What is the motivation for storing related records together in a key

What is the motivation for storing related records together in a key-value store? Explain the idea using the notion of an entity group.