ITSS 3300 Lecture Notes - Lecture 6: Directaccess, Predictive Analytics, Data Quality
25 Jun 2018
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CH 6 – Database and Informational Management
Database: serves many apps by centralizing data and controlling data redundancy and using single
master data
The data hierarchy:
Bit, byte, field, record, file, database.
Problems with the traditional file environment:
-Files maintained separately by diff depts.
-Date redundancy: presence of duplicate data in multiple data files so
that the same data are stored in more than place or location
-Data inconsistency: same attribute may have different values.
-Program data dependence: coupling of data stored in files and specific programs required to update
and maintain those files such that changes in programs require changes to the data.
-Lack of flexibility: cannot deliver ad hoc reports or respond to unanticipated information requirements
in a timely fashion.
-Poor security: access to and dissemination of information may be out of control.
-Lack of data sharing availability
Data model team will review the conceptual data design necessary for the company.
Database management sys (DBMS): software that permits an organization to centralize data, manage
them efficiently, and provide access to the stored data by application programs.
-finds this item in the database and presents it to the application program.
-The logical view- presents data as perceived by end users or business specialists
- physical view- data organized and structured on physical storage media.
RDBMS: relational database management sys
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For PCs and larger computers and mainframes
Better than a file sys tht uses manual sys.
Software tht the allows retrieval of data, series of processes tht involves the DBMS.
Moving data to from data and app.
Represents data as 2D tables.
Each table contains data on entity and attributes
Each column is a field
Table: grid of columns and rows
Rows: records for diff entities
Fields (columns): represents attribute for entity
Key field: field used to uniquely identify each record
Primary key: field in table used for keys
Foreign key: primary key used in second table as look up field to identify records from original
table
An object-oriented DBMS: stores the data and procedures that act on those data as objects that can be
automatically retrieved and shared.
DMS:
-interfaces btwn applications and physical data files
Separates logical and physical views of data( wht the RDBMS does)
Solves problems of traditional file environment
Also allows multiple views of data
Out of the same physical database, diff logical views interpreted
Ex: benefits view and payroll views
Capabilities of DMS:
Data definition: specify the structure of the content of the database.
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find more resources at oneclass.com
Document Summary
Database: serves many apps by centralizing data and controlling data redundancy and using single master data. Date redundancy: presence of duplicate data in multiple data files so that the same data are stored in more than place or location. Data inconsistency: same attribute may have different values. Program data dependence: coupling of data stored in files and specific programs required to update and maintain those files such that changes in programs require changes to the data. Lack of flexibility: cannot deliver ad hoc reports or respond to unanticipated information requirements in a timely fashion. Poor security: access to and dissemination of information may be out of control. Data model team will review the conceptual data design necessary for the company. Database management sys (dbms): software that permits an organization to centralize data, manage them efficiently, and provide access to the stored data by application programs. Finds this item in the database and presents it to the application program.
