Exam 3 IST359

Entity Mapping

Entity Mapping

translates to a relational table

Bridge Table

this is required to map a many-to-many relationship

Mapping

the process of transforming a conceptual model into a logical model

Attribute Mapping

translates to relational tables or columns within a table

Analysis

the process of componentizing a complicated problem to achieve a better understanding of it

Relationship Mapping

translates to foreign key placement

Unique Attribute Type Mapping

translates to setting a unique key constraint

Entity

a thing for which you need to store data

Attributes

characteristics or descriptors of an entity

Relationships

business rules which connect entities together

Required Attribute Type Mapping

translates to not allowing null on the table’s column

Composite Attribute Type Mapping

translates to breaking down the attribute into more than one table column

NOT NULL Foreign Key

this is required to map a weak entity

Unique

an attribute value should be different for each entity

Foreign Key

this is required to map a one to many relationship

Foreign Key w/ Unique Constraint

this is required to map a one to one relationship

Required

an attribute value is mandatory

Normalization

a process applied to relational tables which improves logical design by eliminating data redundancy and inconsistency

Minimal Candidate Key

the smallest number of columns from a data set which can act as primary key

Derived

an attribute value can be calculated from one or more other attributes

Prime Attribute

a column which is key or is part of the key

Composite

an attribute is complex and should be sub-divided in its implementation

Non-Prime Attribute

a column which is not part of the key

Multi-Valued

an attribute contains more than one value

Cardinality

the number of occurrences at minimum and maximum of one entity as it relates to another

Functional Dependence

the key attribute can be used to retrieve one and only one attribute for each non-key column

Partial Functional Dependence

in a key containing more than one column

Transitive Functional Dependence

a non-key column acting as key for another non-key column

Data Migration

the process of transferring data from one source to another

Data Extraction

the process of retrieving data from its source as part of a migration

Weak Entity

an entity which cannot exist without another entity

Data Cleansing

the process of fixing mistakes or cleaning up source data

Data Transformation

the process of breaking up source data into a structure suitable for a target structure

Data Loading

the importation of transformed data into a target data structure

Data Verification

the process of checking whether a migration was successful

Logical Data Model

a relationally-dependent, but DBSM independent model