CS6400 - Exam 3 Online Proctored Exam Questions and Answers | 100% Pass Guaranteed | Graded A+

CS6400 - Exam 3 Online Proctored Exam
Questions and Answers | 100% Pass
Guaranteed | Graded A+


Area of the disk - {✔✔Resolution Result Verified Answers ✔✔}-hold records
of more than one type so that records of different types. good: distribute values
uniformly over the address space, fill buckets as much as possible, avoid collisions



Physical clustering - {✔✔Resolution Result Verified Answers ✔✔}-is used in
object DBMSs to store related objects together in a mixed file.


Operational Data Store - {✔✔Resolution Result Verified Answers ✔✔}-A
subject-oriented, currentvalued, detailed database.



ETL - {✔✔Resolution Result Verified Answers ✔✔}-Extract, Transform, Load


ISAM - {✔✔Resolution Result Verified Answers ✔✔}-Indexed Sequential
Access Method


ordering key field - {✔✔Resolution Result Verified Answers ✔✔}-is used to
physically order the file records on disk

,clustering index - {✔✔Resolution Result Verified Answers ✔✔}-if numerous
records in the file can have the same value for the ordering field— another type
of index, file can have only 1 clustering index.



indexing field - {✔✔Resolution Result Verified Answers ✔✔}-or indexing
attribute, index access structure is usually defined on a single field of a file



Primary Index - {✔✔Resolution Result Verified Answers ✔✔}-is an ordered
file whose records are of fixed length with two fields, and it acts like an access
structure to efficiently search for and access the data records in a data file



index entry - {✔✔Resolution Result Verified Answers ✔✔}-each main
heading, with its locators and sometimes cross-references



anchor record - {✔✔Resolution Result Verified Answers ✔✔}-The first
record in each block of the data file



Dense Index - {✔✔Resolution Result Verified Answers ✔✔}-has an index
entry for every search key value (and hence every record) in the data file



sparse (or nondense) index - {✔✔Resolution Result Verified Answers ✔✔}-
has index entries for only some of the search values

,clustering field - {✔✔Resolution Result Verified Answers ✔✔}-file records
are physically ordered on a nonkey field—which does not have a distinct value for
each record



all-key relation - {✔✔Resolution Result Verified Answers ✔✔}-obvious
redundancy in the relation


X → → Y - {✔✔Resolution Result Verified Answers ✔✔}-X multi-determines
Y


Fourth Normal Form (4NF) - {✔✔Resolution Result Verified Answers ✔✔}-A
table is in 4NF if it is in 3NF and contains no multiple independent sets of
multivalued dependencies.



join dependency (JD) - {✔✔Resolution Result Verified Answers ✔✔}-
specifies a constraint on the states r of R.



Fifth Normal Form (5NF) - {✔✔Resolution Result Verified Answers ✔✔}-A
normal form necessary to eliminate an anomaly where a table can be split apart
but not correctly joined back together.
Also known as Project-Join Normal Form (PJ/NF).


relational design by synthesis - {✔✔Resolution Result Verified Answers
✔✔}-bottom-up approach to design that presupposes that the known
functional dependencies among sets of attributes in the Universe of Discourse
(UoD) have been given as input.

, properties of decompositions - {✔✔Resolution Result Verified Answers
✔✔}-the dependency preservation property and the nonadditive (or lossless)
join property



universal relation - {✔✔Resolution Result Verified Answers ✔✔}-
hypothetical relation containing all the attributes



Armstrong's axioms - {✔✔Resolution Result Verified Answers ✔✔}-IR1
(reflexive rule)2: If X Y, then X →Y. IR2 (augmentation rule)3: {X → Y} |=XZ → YZ.
IR3 (transitive rule): {X → Y, Y → Z} |=X → Z.



Proof of IR2 (contradiction) - {✔✔Resolution Result Verified Answers ✔✔}-
the rule does not hold and shows that this is not possible



Proof of IR1 - {✔✔Resolution Result Verified Answers ✔✔}-Suppose that X
Y and that two tuples t1 and t2 exist in some relation instance r of R such that t1
[X] = t2 [X]. Then t1[Y] = t2[Y] because X Y; hence, X → Y must hold in r.



Proof of IR3 - {✔✔Resolution Result Verified Answers ✔✔}-Assume that (1)
X → Y and (2) Y → Z both hold in a relation r., X → Z must hold in r.



Minimal Cover (of a set of FDs) - {✔✔Resolution Result Verified Answers
✔✔}-A minimal cover of a set of FDs G is a minimal set of FDs that is equivalent
to G


extraneous attribute - {✔✔Resolution Result Verified Answers ✔✔}-if we
can remove it without changing the closure of the set of dependencies.