Data Storage and Extraction (Information Quality (Consistency (Bugs are…
Data Storage and Extraction
DATA MODELING AND TABLE MAPPING
physical data model
model is constructed through collaboration with the business stakeholders to reflect the initial business requirements that the data must support.
Entity-Relationship Diagramming (ERD)
It includes specific standardized notation to indicate each piece of data that needs to be included in the system as well as how the data should be organized and separated to maintain the highest quality (e.g. maximizing the speed of data access and reducing data redundancy).
(A Single Occurrence) :
verbs that describe how entities relate to each other; for example (the relationships are capitalized), 'Customer BUYS Product,' 'Employee FILES Time Sheet,' 'Salesperson PLACES Order.' An entity-relationship-entity phrase is called a "relationship entity pair," which is a fashionable mechanism for representing relationships. Relationship entity pairs are bidirectional. Therefore, 'Customer Buys Product' is the same as 'Product is Bought by Customer.'
usually expressed as simply "one" or "many."
For example, a husband can have only one wife, while a parent can have many children
Maximum VS. Minimum
(Properties) These are the properties that the entities care about. They are characteristics of the entities
Color, Employment Date, Name, and Social Security Number.
are persons, places, or things about which an organization wishes to save information. (A Concept)
a logical concept in the mind of the analyst that represents a category of objects that have common characteristics or attributes that we want to store. For example, when we think about police detectives we have a concept--a logical abstraction--in our mind that represents a type of person who investigates crimes.
When we label entities, we use the singular tense because each entity represents a category.
Example: Employee, Order, and Time Sheet
is the process used to define data requirements needed to support the business processes within organizations.
are collections of data organized for search and retrieval
Relational Databases: Resolves the problem of data redundancy
DBMS (Database Management Systems)
: the software system used to store data electronically and provide advanced features for ensuring and maintaining data quality as well as managing the security and availability of the data
Example: Access, SQL Server, Oracle, DB2, or others.
Levels of Granularities
Information is in raw data form
Data has been summarized even further.
Types of Information
refers to the data that is generated by real-time business processes
Stored/ required for everyday business processes or operations.
refers to any data or information that can be used to make intelligent inferences relevant to the organization, help solve unstructured business problems, and support higher-level, ad-hoc decision making.
Is this information correct?
Bugs are common
(connected to uniqueness, but not the same)
Happens when the exact same piece is sorted multiple times
Is all or part of a value missing?
the difference between the current time and when the data was stored