Chapter 6 McGraw Hill Notes- Databases
Overview Of Topics
1. Traditional File management systems
2. DBMS (Database Management Systems)
3. Relational databases
4. Non Relational databases
5. Big Data
6. Data warehouses
7. Data and web mining
8. Database policies and procedures
Database and DBMS Overview
- Database - collection of data organized so a computer can quickly search/retrieve
information
- It is a collection of tables, and the relationships between those tables
- THINK: Imagine you own an online business selling stickers: you need to keep track of
your inventory, customers, advertising, and spending information. You could put this in a
spreadsheet or a notebook.
- Databases are similar to this notebook of your information, but has an additional feature
of being able to respond to your data. You can ask the database questions and get
almost immediate answers. Questions include:
- What month do most sales of stickers occur?
- How many customers viewed the ad on sites vs how many actually bought the
product?
- What items sell best to customers in the 20-35 year old age range?
➔ Today's businesses have so much data that it's impossible to imagine them not using a
database to manage it
➔ With the increased use of Internet, data is continuously changing and needs to be
evaluated in “real time”
- Database Management System (DBMS)- computer program that creates, processes,
and administers a database
- Most organizations don't develop their own DBMS because it is so complicated
- They select a DBMS created from a software vendor (Microsoft, Oracle, IBM)
- DBMS is not a database
- DBMS is a program to organize and administer a database; organizes the data
found in a database
- A database is a collection of tables, relationships, and metadata
DBMS can solve File Management Issues
- Less data redundancy (duplication of data)
- Ie. if you manage data of a gym and a customer is enrolled in multiple gym
classes, the same customer details will be stored twice. This takes up storage,
leading to higher storage costs and inefficient access to data.
- Less data inconsistency- (inaccurate data)
, - Ie. if the customer from the previous example changed her address, it's possible
only one record is changed, and data inconsistency will occur
- More data security- Using a DBMS ensures only authorized users can access the data
- Different types of users are assigned different sets of access rules, protects
against identity theft, data leaks, and misuse of data
Fields and Records
- A field is a column in a table that represents a characteristic of something/someone
- Can hold customer ID, (primary keys), addresses, email, phone numbers
- A record is a row in the table that includes a collection of fields
- A record that corresponds to a field of a Customer ID could include their mailing
address
Relational Databases
Structure of a relational database
- Row and column- based table structure to connect data through relationships
- Uses links called “relationships” between tables
- Tables with rows and columns hold information in the database
- Row- Record: also called objects, a row in a database table that includes a
collection of fields
- Column- Field: a column in a database table that represents a characteristic of
something or someone
- THINK: the record is like an event title, the field is the time, date, and location of
the event
- A common field (column/description) is used to create the relationship between data
- Rows among multiple tables are made related using foreign keys
- Foreign key: a field linked to another tables key field in the connection between
the two tables in a database
Relational database operations
- In general databases are designed to maintain data about various types of data:
- Objects (like stock or inventory)
- Events (transactions, returns, exchanges)
- People (customers, employees, vendors)
- Places (procurement centers or wholesalers)
- DBMS operations include creation, reading, updating, and deletion of data in a
database
- Includes security features, access controls, and enable managers to manipulate, query
and store information
Tables, Keys, and Referential Integrity
Tables
- A table in a database is a collection of associated records
- Small businesses might have a database with a table with customer demographics, a
table with customer orders, a table with inventory, and a table about your employees
Primary and Foreign keys
- Primary key- unique to each item in each row in a database, identities all records in a
table
- Contains a unique value so no two records have the same one
Overview Of Topics
1. Traditional File management systems
2. DBMS (Database Management Systems)
3. Relational databases
4. Non Relational databases
5. Big Data
6. Data warehouses
7. Data and web mining
8. Database policies and procedures
Database and DBMS Overview
- Database - collection of data organized so a computer can quickly search/retrieve
information
- It is a collection of tables, and the relationships between those tables
- THINK: Imagine you own an online business selling stickers: you need to keep track of
your inventory, customers, advertising, and spending information. You could put this in a
spreadsheet or a notebook.
- Databases are similar to this notebook of your information, but has an additional feature
of being able to respond to your data. You can ask the database questions and get
almost immediate answers. Questions include:
- What month do most sales of stickers occur?
- How many customers viewed the ad on sites vs how many actually bought the
product?
- What items sell best to customers in the 20-35 year old age range?
➔ Today's businesses have so much data that it's impossible to imagine them not using a
database to manage it
➔ With the increased use of Internet, data is continuously changing and needs to be
evaluated in “real time”
- Database Management System (DBMS)- computer program that creates, processes,
and administers a database
- Most organizations don't develop their own DBMS because it is so complicated
- They select a DBMS created from a software vendor (Microsoft, Oracle, IBM)
- DBMS is not a database
- DBMS is a program to organize and administer a database; organizes the data
found in a database
- A database is a collection of tables, relationships, and metadata
DBMS can solve File Management Issues
- Less data redundancy (duplication of data)
- Ie. if you manage data of a gym and a customer is enrolled in multiple gym
classes, the same customer details will be stored twice. This takes up storage,
leading to higher storage costs and inefficient access to data.
- Less data inconsistency- (inaccurate data)
, - Ie. if the customer from the previous example changed her address, it's possible
only one record is changed, and data inconsistency will occur
- More data security- Using a DBMS ensures only authorized users can access the data
- Different types of users are assigned different sets of access rules, protects
against identity theft, data leaks, and misuse of data
Fields and Records
- A field is a column in a table that represents a characteristic of something/someone
- Can hold customer ID, (primary keys), addresses, email, phone numbers
- A record is a row in the table that includes a collection of fields
- A record that corresponds to a field of a Customer ID could include their mailing
address
Relational Databases
Structure of a relational database
- Row and column- based table structure to connect data through relationships
- Uses links called “relationships” between tables
- Tables with rows and columns hold information in the database
- Row- Record: also called objects, a row in a database table that includes a
collection of fields
- Column- Field: a column in a database table that represents a characteristic of
something or someone
- THINK: the record is like an event title, the field is the time, date, and location of
the event
- A common field (column/description) is used to create the relationship between data
- Rows among multiple tables are made related using foreign keys
- Foreign key: a field linked to another tables key field in the connection between
the two tables in a database
Relational database operations
- In general databases are designed to maintain data about various types of data:
- Objects (like stock or inventory)
- Events (transactions, returns, exchanges)
- People (customers, employees, vendors)
- Places (procurement centers or wholesalers)
- DBMS operations include creation, reading, updating, and deletion of data in a
database
- Includes security features, access controls, and enable managers to manipulate, query
and store information
Tables, Keys, and Referential Integrity
Tables
- A table in a database is a collection of associated records
- Small businesses might have a database with a table with customer demographics, a
table with customer orders, a table with inventory, and a table about your employees
Primary and Foreign keys
- Primary key- unique to each item in each row in a database, identities all records in a
table
- Contains a unique value so no two records have the same one
