rabeel
01-05-2012, 03:08 AM
Cs403 database quiz on 4 January 2012-01-04
Please download the PDF to get full marks
A relation is said to be in BCNF when
it has overlapping composite keys
In vertical partitioning if we divide a table into two vertical partitions then efficiency of those applications will be reduced which used to.
Access data from second vertical partition
Attributes are (i) properties of relationship (ii) attributed to entities (iii) properties of members of an entity set
General reasoning for horizontal or vertical partitioning is.
Increasing the consistency
Given the following relation it is not 3 NF because Student (roll no, name, course no, course max. marks, year of study, address), where roll no is PK
it has more than 3 non-key attributes
BCNF is needed because
A second Normal Form (2 NF) relation should
be in 1 NF
Boye Codd Normal Form (BCNF) is needed when
there are two or more possible composite overlapping keys and one attribute
of a composite key is dependent on an attribute of another composite key
A relation is said to be in 3 NF if (i) it is in 2 NF (ii) non-key attributes are independent of one another (iii) key attribute is not dependent on part of a composite key (iv) has no multi-valued dependency
i and ii
The process of normalization
requires one to understand dependency between attributes
ramiz
Atomicity is a feature of ______.
If A -> B and A -> C, then A -> BC The Inference Rule applies is;
Augmentation
A relation is said to be in BCNF when
it has no overlapping composite keys which have related attributes
A 3 NF relation is converted to BCNF by
dependent attributes of overlapping composite keys are put in a separate relation
Normalization is a process of restructuring a relation to
minimize duplication of data in a database
An attribute y may be functionally dependent on (i) a composite attribute x,y (ii) a single attribute x (iii) no attribute
i and ii
Consider the following relation vendor_order (vendor no, order no, vendor name, qty supplied , price/unit) where 'vendor no, order no' is PK. The second normal form relations are
vendor (vendor no, vendor name, qty supplied, price/unit), vendor no is PK
vendor order (order no, vendor no), order no and vendor no is PK
Normalization of database is essential to (i) avoid accidental deletion of required data when some data is deleted (ii) eliminate inconsistencies when a data item is modified in the database (iii) allows storage of data in a computer’s disk (iv) use a database management system
i and ii
Please download the PDF to get full marks
A relation is said to be in BCNF when
it has overlapping composite keys
In vertical partitioning if we divide a table into two vertical partitions then efficiency of those applications will be reduced which used to.
Access data from second vertical partition
Attributes are (i) properties of relationship (ii) attributed to entities (iii) properties of members of an entity set
General reasoning for horizontal or vertical partitioning is.
Increasing the consistency
Given the following relation it is not 3 NF because Student (roll no, name, course no, course max. marks, year of study, address), where roll no is PK
it has more than 3 non-key attributes
BCNF is needed because
A second Normal Form (2 NF) relation should
be in 1 NF
Boye Codd Normal Form (BCNF) is needed when
there are two or more possible composite overlapping keys and one attribute
of a composite key is dependent on an attribute of another composite key
A relation is said to be in 3 NF if (i) it is in 2 NF (ii) non-key attributes are independent of one another (iii) key attribute is not dependent on part of a composite key (iv) has no multi-valued dependency
i and ii
The process of normalization
requires one to understand dependency between attributes
ramiz
Atomicity is a feature of ______.
If A -> B and A -> C, then A -> BC The Inference Rule applies is;
Augmentation
A relation is said to be in BCNF when
it has no overlapping composite keys which have related attributes
A 3 NF relation is converted to BCNF by
dependent attributes of overlapping composite keys are put in a separate relation
Normalization is a process of restructuring a relation to
minimize duplication of data in a database
An attribute y may be functionally dependent on (i) a composite attribute x,y (ii) a single attribute x (iii) no attribute
i and ii
Consider the following relation vendor_order (vendor no, order no, vendor name, qty supplied , price/unit) where 'vendor no, order no' is PK. The second normal form relations are
vendor (vendor no, vendor name, qty supplied, price/unit), vendor no is PK
vendor order (order no, vendor no), order no and vendor no is PK
Normalization of database is essential to (i) avoid accidental deletion of required data when some data is deleted (ii) eliminate inconsistencies when a data item is modified in the database (iii) allows storage of data in a computer’s disk (iv) use a database management system
i and ii