Exam (elaborations)
CSE 511 Midterm Exam With Complete Solutions Latest Update 100% Correct
- Course
- Institution
CSE 511 Midterm Exam With Complete Solutions Latest Update 100% Correct...
[Show more]
Content preview
CSE 511 Midterm Exam With Complete Solutions LatestUpdate 100% Correct
Transaction - ANSWER User program that can either read or write data from or to the
database system
ACID - ANSWER Atomicity, Consistency, Isolation and Durability
ACID - Atomic - ANSWER All or nothing - Transaction must be completed in full or not at
all (no subdividing)
ACID - Consistency - ANSWER Transactions will transform the database from one
consistent state to another. There are no violations of integrity constraints.
ACID - Isolated - ANSWER Transactions execute independently of one another.
Database changes are not revealed to one another until after a transaction has
completed.
Serializable - even if some transactions are executed concurrently the results must be
the same as if they were executed serially in some order.
ACID - Durable - ANSWER Database changes are permanent.
Which of the following are the advantages of using a DBMS? - ANSWER Data
Independence, Data Security, Concurrency, Data Administration. (Concurrent
Access/Crash Recovery, Data Integration/Security, Reduced App Development Time)
In which of the following levels of abstraction is the logical structure defined? - ANSWER
Conceptual Schema
,What does physical level of schema define? - ANSWER files and indexes used
What do views do? - ANSWER describe how user sees data (ex: course_info(cid:string,
enrollmen:int))
Which of the following is correct about weak entities?
a. Owner entity set and the weak entity set can participate in a many-to-many
relationship.
b. Owner entity set and weak entity set must participate in one-to-many relationship.
c. Weak entity must have total participation in the identifying relationship set.
d. The weak entities cannot exist independently of the owner entity - ANSWER B: For
every owner set and weaker set participating in one-to-many relationship set(one
owner, and many weak entities)
C: In this identifying relationship set, weak entities must participate in total participation
(If the owner entity is deleted, then all the owned weak entities have to be deleted too.)
Can be uniquely identified only by considering the primary key of another entity, called
the owner entity
SQL is a ______________ language - ANSWER declarative (tells what data is to be
retrieved but does not tell the system how to retrieve it.
Which query can be used to list the student information for computer science majors [C]
who are not double majors in electrical engineering [E]? - ANSWER C-E (difference)
Which of the following is true when using Heap Files?
a. Heap Files are efficient for the loading of bulk data.
b. Heap Files are efficient for sorting.
c. Heap Files are not efficient for selective queries.
, d. Heap Files are not efficient while working on relatively small relations - ANSWER a.
Heap Files are efficient for loading bulk data.
c. Heap Files are not efficient for selective queries.
Heap files are not efficient for sorting and may be time-consuming.
Heap files are efficient for working on relatively small relations since indexing
overheads are avoided.
What is the memory hierarchy? - ANSWER Secondary Storage (Hard Disk) -> Computer
Main Mem -> Caches -> Registers
What storage is the fastest? - ANSWER Registers
Which component loads the pages from hard disk to memory? - ANSWER Buffer
Manager
stages pages from external storage to main memory buffer pool so DB can process info
(read/write)
File and index layers call into buffer manager
Main memory is smaller compared to the size of disk so you bring everything into main
memory at once using buffer manager
Which of the following question(s) should you have already answered before you
actually create an index?
a. What field(s) should be the search key?
b. Should you build several indexes?
c. Which relations should have indexes?
d. What record(s) is to be the key for a search? - ANSWER a. What field(s) is to be the
key for a search?
b. Should multiple indexes be created?
c. Which relations is the index to be created for?
The benefits of buying summaries with Stuvia:
Guaranteed quality through customer reviews
Stuvia customers have reviewed more than 700,000 summaries. This how you know that you are buying the best documents.
Quick and easy check-out
You can quickly pay through credit card or Stuvia-credit for the summaries. There is no membership needed.
Focus on what matters
Your fellow students write the study notes themselves, which is why the documents are always reliable and up-to-date. This ensures you quickly get to the core!
Frequently asked questions
What do I get when I buy this document?
You get a PDF, available immediately after your purchase. The purchased document is accessible anytime, anywhere and indefinitely through your profile.
Satisfaction guarantee: how does it work?
Our satisfaction guarantee ensures that you always find a study document that suits you well. You fill out a form, and our customer service team takes care of the rest.
Who am I buying these notes from?
Stuvia is a marketplace, so you are not buying this document from us, but from seller Easton. Stuvia facilitates payment to the seller.
Will I be stuck with a subscription?
No, you only buy these notes for $17.99. You're not tied to anything after your purchase.
Can Stuvia be trusted?
4.6 stars on Google & Trustpilot (+1000 reviews)
67163 documents were sold in the last 30 days
Founded in 2010, the go-to place to buy study notes for 14 years now