Please enable JavaScript.

Coggle requires JavaScript to display documents.

Zybooks 1 - Coggle Diagram

- - - - Non commercial
      - education
    - - commercial databases
      - MySQL Server and additional administrative applications
  - - - Allows developers to connect to the database server, perform administrative functions and execute SQL statements
      - To run the Command-Line Client, a user must first open a command prompt or Terminal. Some process
      - Comes with a default "world" database for playing around
      - Returns an error code when SQL statement is syntactically incorrect
  - - - Administration
      - Schemas
- - - - uses catalog to perform query optimization. This is not necessarily necesary
        
        Storage manager translates the query processor instructions to file-system commands and uses indexes to quickly locate the data.
        
        Transaction manager logs, inser, updata and delete queries and the result is sent back to the application
  - - - like a spreadsheet
      - each row is an object
      - all relational database systems support SQL
      - Relational databases not necessarily designed for big data, which often has poorly structured or missing information.
      - Its weaknesses caus non-relational systems
        
        NoSQL is optimized for big data
        
        Most data management systems are free now
- - - - write applications that use database
    - - usually access via application
- - - - Analysis
        
        Analyze requirements without regard to a specific database system
        
        Requirements are represented as entities, relationships and attributes
        
        an entity is a person, place, activity or thing.
        
        A relationship is a link between entities,.
        
        An attribute si a descriptive property of an entity
        
        The three things can be depicted in ER diagrams
        
        Rectangles are entities
        
        Lines between rectangles represent relationships
        
        Text inside rectangles and below entity names represent attributes
        
        Also known as "conceptual design", "entity-relationship modeling", "requirements definition"
      - Logical design
        
        Implements database requirements in a specific database system
        
        For relational database systems
        
        converts entities, relationships, and attributes into tables, keys, and columns
        
        A key is a column used to identify individual rows of a table.
        
        All specified in SQL with CREATE TABLE statements
        
        Depicted in a table diagram
        
        Similar to ER diagrams, but more detailed
        
        Rectangles represent tables.
        
        Text in rectagles and below table names represent columns
        
        Solid bullets indicate key columns
        
        Empty bullets and arrows indicate columns that refer to keys
        
        Called the database schema
      - Physical Design
        
        Adds indexes and specifies how tables are organized on storage media
        
        design diagrams not commonly used
        
        Logical design affects query result. Physical design does not.
        
        Physical design never affects query results - data independence
- - - - The select query (R) can return nothing
    - - INSERT
      - SELECT
      - UPDATE
      - DELETE