1.3.2 database

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Created by
Salima Hassan

Cards (66)

  • database
    comma seperated value(CSV)
    how does this word
    1)each record is put on its own line
    2) each field is seperated by a special character such as comma
  • database
    comma seperated value(CSV)
    this is a method of what
    of storing a record
  • Database
    types of databases
    flat-file databases
    types of data in flat file databases
    primary key
    what does primary key mean
    is a field (columns) used to uniquely identify a specific rows of data in a table
    example: in college each student has a ID that is unique to them that can be used as a primary key
  • Database
    types of databases
    flat-file databases
    types of data in flat file databases
    redudant data
    what does redundant data mean
    is data that is repeated in a database
  • Database
    types of databases
    flat-file databases
    types of data in flat file databases
    redundant data
    a single table file is inefficient why?
    as it is full of redundant data
  • Database
    types of databases
    flat-file databases
    types of data in flat file databases
    there are two types
    -redundant data
    -primary key
  • Database
    types of databases
    flat-file databases
    what is a flat file database
    Data that is stored in plain files
    -are used to store records of information in order to be searched or queried at a later date
  • Database
    types of databases
    flat-file databases
    what is the structure of flat file database
    -is one that has a single table to store data about an 'entity'
    -the table stores data in fields(columns) such as date of birth
    -a records(row) of information is a complete set of fields put together.
    --this could be a persons details:name, age, gender
  • Database
    types of databases
    Relational Databases
    foreign key
    what does foreign key means
    this is when the primary key of one table is placed into another table
    example: student ID was in the same table as student and parent table; this student ID is a primary key in student but a foreign key in family table
  • Database
    types of databases
    Relational Databases
    secondary key
    what does secondary key mean
    used to locate one (or more) records within a database
    -do not need to be unique
    --example: parents may not know students ID but can locate it by thier last name in the database
  • Database
    types of databases
    Relational Databases
    what does each table contain
    contains data on one entity(e.g student or parents) when you link one table to another(this is called a relationship)
    --each table then has a relationship to other tables using primary and foreign keys
  • Database
    types of databases
    Relational Databases
    what does relational database mean
    data stored in a clear organised manner across multiple tables
  • Database
    what are fields
    is a particular piece of data encapsulated within a class or object(these are columns in a table)
  • database
    what are records
    data that has several parts known as records (can be divided into data fields), a row in a table
  • database
    what are records made out of
    made up of fields
    example of records:
    a person could be represented as a record where the fields include their name, age and address
  • Database
    what are the advantages of records
    -very simple, text-based format
    -can be read by many applications
    -easy to use in programs
  • Database
    what are the disadvantages of records
    -inefficient for large data sets
    -can only store text data
    -no built-in means of sorting or searching
  • Database
    what does this mean
    computerised system that makes it easy to search, select and store information
  • database
    what is a entity
    objects that exist
  • Managing database
    normalisation to 3NF
    First normal form(1NF)
    for a database to be 1NF what does it have to follow
    -no column with repeated or similar data
    -each row is unique with a primary key
    -each field must have a unique name
  • Managing database
    normalisation to 3NF
    indexing
    what does this mean
    is a method used to store the position of each record ordered by a certain attribute
  • Managing database
    normalisation to 3NF
    indexing
    what is it used for
    used to look up and access data quickly
  • Managing database
    normalisation to 3NF
    indexing
    what key is automatically indexed
    primary key
  • Managing database
    normalisation to 3NF
    Second normal form(2NF)
    for a database to be 2NF what does it have to be
    it has to be in 1NF
  • Managing database
    normalisation to 3NF
    Second normal form(2NF)
    what does each field have to rely on
    on the primary key to be unique
  • Managing database
    normalisation to 3NF
    Third normal form(3NF)
    for a database to be 3NF, it has to be in what
    has to be in 2NF
  • Managing database
    normalisation to 3NF
    Third normal form(3NF)
    no field should rely on what
    on another non-key field
    example: a database should not store someone's age and data of birth
  • Managing database
    normalisation to 3NF
    unnormalisation data
    what is this
    before going to 1NF, a flat-file table structure is put together
  • Managing database
    normalisation to 3NF
    what are 3 stages of normalisation
    -first normal form(1NF)
    -second normal form(2NF)
    -third normal form(3NF)
  • Managing database
    normalisation to 3NF
    what can normalisation turn flat file to
    into a relational database
  • Managing database
    normalisation to 3NF
    what does normalisation mean
    normalisation data is a process which makes a database more efficent to run and store
  • Managing database
    referential integrity
    what does it prevent to do
    prevents a record containing a foreign key from using a value that doesn't exist in the linked table where its a primary key
  • Managing database
    referential integrity
    what does this help to ensure
    ensure no data redundancy and inaccuracies between linked tables
  • managing databases
    entity relationship modeling
    methods of data capture, management and exchange
    capturing data
    what does this mean
    -is a careful consideration that should be made and selecting what will suit your purpose best
    -this could be a data collection form that the user fills out and then is entereed by the data operator(or the user could be present when this happens)
  • managing databases
    entity relationship modeling
    methods of data capture, management and exchange
    database management
    name the 3 different DBMS
    -my SQL
    -Oracle
    -BigTable
  • managing databases
    entity relationship modeling
    methods of data capture, management and exchange
    database management
    what does this mean
    the management of database is handled by DataBase Management System(DBMS)
  • managing databases
    entity relationship modeling
    methods of data capture, management and exchange
    exchanging data
    exchanging data can happen through formats such as XMH and SON
    What does these formats contain
    mark up that make the data interchange. each organisation's system can be configured to read and write to each other's database
  • managing databases
    entity relationship modeling
    methods of data capture, management and exchange
    exchanging data
    what is one way that data can be exchanged
    through comma sperated value(CSV) file
  • managing databases
    entity relationship modeling
    methods of data capture, management and exchange
    selecting data
    what does this mean
    these should be important and only then stored
    example: CCTV footage of a crime happening is important not when it isnt happening
  • Managing databases
    Entity relationship Modeling
    Many to many
    What does this mean
    Is when several entities are linked to several other entities