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
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