INSY 3304 Midterm Review Questions And Answers Latest Updates
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INSY 3304
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INSY 3304
Entity Integrity - ️️is a basic constraint of database relational model (abbreviated
RM) that refers to the morphology of the primary key but afterwards, the same format is
applied to the foreign key and, also to any of simple components of any of two. The
relational model states that every ...
INSY 3304 Midterm Review
Entity Integrity - ✔️✔️is a basic constraint of database relational model (abbreviated
RM) that refers to the morphology of the primary key but afterwards, the same format is
applied to the foreign key and, also to any of simple components of any of two. The
relational model states that every relation (or table) must have an identifier, called the
primary key (abbreviated PK), in such a way that every row of the same relation be
identifiable by its content, that is, by a unique and minimal value. The PK is a not empty
set of attributes (or columns)
Basic concepts about the relational database model
Ð Entity
Ð Attribute
Ð Table
Ð Row
Ð Column
Ð Attribute domain - ✔️✔️Entity -anything about which data are to be collected and
stored
Functions of a DBMS - ✔️✔️Indexing
Views
Security
Integrity
Concurrency
Backup/Recovery
Design
Documentation
Update/Query
The different types of Database Systems (users) - ✔️✔️Desktop Database - one user
Multiple user database - a.k.a. Workgroup database has 50 or less
Enterprise - More than 50 users
The different types of Database systems (Locations) - ✔️✔️Centralized Database -
which supports data located on a single site
Distributed database - data stored on multiple locations
Database models
-Types - ✔️✔️Type and Extent of Use - Operational Database - day to day data
transactions, accounting, production, inventory transactions, sales transactions, payroll,
and POS systems
, Decision Support - Stored in data warehouses stores data used fir statistically like 5 yr
sales data.
XML- (Extensive Markup Language) data element in textual format provides a
semistructured data create our own tags, ie last name tags to a customer, but diff to
html is that we can customize the tags
Database model Structures - ✔️✔️Unstructured Data - having data stored on multiple
locations
Structured Data -data resulting from formatting or processing data to give it structure
Semistructured - data processed to some extent
Database model Advantages, and Disadvantages - ✔️✔️improve data sharing, multiple
users, data security, Data Integration, minimizes data inconsistency
Table -Table(Relation) 2 dimensional structure or matrix of rows and columns each row
and column intersection represent a data value.
Tables represent entities
Rows referred to as tuples
Column referred to a attribute
Attribute Domain - set of values allowed in an attribute
Primary key - ✔️✔️Attribute or combination of attributes that uniquely identifies any
given row
(Cannot contain NULL entries)
Secondary Key - ✔️✔️Secondary key: Key used strictly for data retrieval purposes
Attribute - ✔️✔️a characteristic of an entity
Entity - ✔️✔️anything about which data are to be collected and stored
Table - ✔️✔️(Relation) 2 dimensional structure or matrix of rows and columns each
row and column intersection represent a data value.
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