CS6400 - Exam 3
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1. logical (or concep- how users interpret the relation schemas and the meaning of their attributes
tual) level
2. implementation how the tuples in a base relation are stored and updated
(or physical
storage) level
3. bottom-up design (also called design by synthesis) considers the basic relationships among
methodology individual attributes as the starting point and uses those to construct relation
schemas
4. top-down design (also called design by analysis) starts with a number of groupings of attributes
methodology into relations that exist together naturally
5. measures to deter- Making sure that the semantics of the attributes is clear in the schema
mine the quality Reducing the redundant information in tuples
of relation schema Reducing the NULL values in tuples
design Disallowing the possibility of generating spurious tuples
6. semantics of a re- refers to its meaning resulting from the interpretation of attribute values in a
lation tuple
7. update anomalies can be classified into insertion anomalies, deletion anomalies, and modification
anomalies
8. Insertion Anom- occur when users attempt to store an attribute value in the system but they
alies cannot because the value of another unnecessary but required attribute is not
known
9. Deletion Anom- occur when a value for one attribute that users wish to keep is unexpectedly
alies removed when a value for another attribute is deleted
10. Modification occur when changes to multiple instances of an entity (rows of a table) are
Anomalies needed to effect an update to a single value of an attribute
, CS6400 - Exam 3
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11. Spurious tuples Tuples generated by joining two relations on attributes that are not keys or
foreign keys on these relations.
12. Waste of storage due to NULLs and the difficulty of performing selections, aggregation opera-
space tions, and joins due to NULL values
13. A functional de- occurs when the attribute A uniquely determines B. A = left-hand side,
pendency (A->B) B=right-hand-side.
-is a property of the semantics or meaning of the attributes.
14. FD or f.d. abbreviation for functional dependency
15. Candidate Key An attribute, or combination of attributes, that uniquely identifies a row in a
relation.
16. legal relation Relation extensions r(R) that satisfy the functional dependency constraints
states (or legal ex-
tensions) of R
17. FD cannot be in- must be defined explicitly by someone who knows the semantics of the attrib-
ferred automati- utes of R.
cally
18. diagrammatic no- isplaying FDs: Each FD is displayed as a horizontal
tation
19. Normalization of a process of analyzing the given relation schemas based on their FDs and
Data primary keys to achieve the desirable properties of (1) minimizing redundancy
and (2) minimizing the insertion, deletion, and update anomalies
20. Boyce-Codd Nor- A special type of third normal form (3NF) in which every determinant is a
mal Form (BCNF) candidate key. A table in BCNF must be in 3NF.
, CS6400 - Exam 3
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21. normal form test is decomposed into smaller relation schemas that contain a subset of the
attributes and meet the test that was otherwise not met by the original relation.
22. nonadditive join or lossless join property, guarantees that the spurious tuple generation prob-
lem does not occur
23. dependency ensures that each functional dependency is represented in some individual
preservation relation resulting after decomposition
property
24. superkey any key that uniquely identifies each row
25. key of a relation schema R = {A1, A2, ... , An} is a set of attributes S †R with the
property that no two tuples t1 and t2 in any legal relation state r of R will have
t1[S] = t2[S].
26. primary key A field (or group of fields) that uniquely identifies a given entity in a table
27. prime attribute A key attribute; that is, an attribute that is part of a key or is the whole key.
28. nonprime at- An attribute that is not part of a key.
tribute
29. First Normal Form A relation that has a primary key and in which there are no repeating groups.
(1NF) 1NF disallows relations within relations or relations as attribute values within
tuples. all domain values are atomic.
30. Second Normal is based on the concept of full functional dependency. a relation is in 1NF and
Form (2NF) there are no partial dependencies. every nonkey attribute is fully dependent on
the key.
31. full functional de- removal of any attribute A from X means that the dependency does not hold
pendency anymore
Study online at https://quizlet.com/_c5ho2k
1. logical (or concep- how users interpret the relation schemas and the meaning of their attributes
tual) level
2. implementation how the tuples in a base relation are stored and updated
(or physical
storage) level
3. bottom-up design (also called design by synthesis) considers the basic relationships among
methodology individual attributes as the starting point and uses those to construct relation
schemas
4. top-down design (also called design by analysis) starts with a number of groupings of attributes
methodology into relations that exist together naturally
5. measures to deter- Making sure that the semantics of the attributes is clear in the schema
mine the quality Reducing the redundant information in tuples
of relation schema Reducing the NULL values in tuples
design Disallowing the possibility of generating spurious tuples
6. semantics of a re- refers to its meaning resulting from the interpretation of attribute values in a
lation tuple
7. update anomalies can be classified into insertion anomalies, deletion anomalies, and modification
anomalies
8. Insertion Anom- occur when users attempt to store an attribute value in the system but they
alies cannot because the value of another unnecessary but required attribute is not
known
9. Deletion Anom- occur when a value for one attribute that users wish to keep is unexpectedly
alies removed when a value for another attribute is deleted
10. Modification occur when changes to multiple instances of an entity (rows of a table) are
Anomalies needed to effect an update to a single value of an attribute
, CS6400 - Exam 3
Study online at https://quizlet.com/_c5ho2k
11. Spurious tuples Tuples generated by joining two relations on attributes that are not keys or
foreign keys on these relations.
12. Waste of storage due to NULLs and the difficulty of performing selections, aggregation opera-
space tions, and joins due to NULL values
13. A functional de- occurs when the attribute A uniquely determines B. A = left-hand side,
pendency (A->B) B=right-hand-side.
-is a property of the semantics or meaning of the attributes.
14. FD or f.d. abbreviation for functional dependency
15. Candidate Key An attribute, or combination of attributes, that uniquely identifies a row in a
relation.
16. legal relation Relation extensions r(R) that satisfy the functional dependency constraints
states (or legal ex-
tensions) of R
17. FD cannot be in- must be defined explicitly by someone who knows the semantics of the attrib-
ferred automati- utes of R.
cally
18. diagrammatic no- isplaying FDs: Each FD is displayed as a horizontal
tation
19. Normalization of a process of analyzing the given relation schemas based on their FDs and
Data primary keys to achieve the desirable properties of (1) minimizing redundancy
and (2) minimizing the insertion, deletion, and update anomalies
20. Boyce-Codd Nor- A special type of third normal form (3NF) in which every determinant is a
mal Form (BCNF) candidate key. A table in BCNF must be in 3NF.
, CS6400 - Exam 3
Study online at https://quizlet.com/_c5ho2k
21. normal form test is decomposed into smaller relation schemas that contain a subset of the
attributes and meet the test that was otherwise not met by the original relation.
22. nonadditive join or lossless join property, guarantees that the spurious tuple generation prob-
lem does not occur
23. dependency ensures that each functional dependency is represented in some individual
preservation relation resulting after decomposition
property
24. superkey any key that uniquely identifies each row
25. key of a relation schema R = {A1, A2, ... , An} is a set of attributes S †R with the
property that no two tuples t1 and t2 in any legal relation state r of R will have
t1[S] = t2[S].
26. primary key A field (or group of fields) that uniquely identifies a given entity in a table
27. prime attribute A key attribute; that is, an attribute that is part of a key or is the whole key.
28. nonprime at- An attribute that is not part of a key.
tribute
29. First Normal Form A relation that has a primary key and in which there are no repeating groups.
(1NF) 1NF disallows relations within relations or relations as attribute values within
tuples. all domain values are atomic.
30. Second Normal is based on the concept of full functional dependency. a relation is in 1NF and
Form (2NF) there are no partial dependencies. every nonkey attribute is fully dependent on
the key.
31. full functional de- removal of any attribute A from X means that the dependency does not hold
pendency anymore
