6.2 data formats

• Alphabetically list the data types:

  Boolean

  Character

  Date

  Float

  Integer

  String
• A csv has what delimiter?

  comma
• Name the 5 main plaintext file types(full names)?

  American standard code for information exchange

  Comma seperated values

  Fixed width text

  Javascript object notation

  Extensible markup language
• Which of the 5 main file types doesn't have shorthand?

  Fixed width text
• HOw many letters are in the alphabet?

  26
• what is a delimiter?

  Seperater of columns
• CSV is used to export and import data between software that may support otherwise incompatible languages
• CSV is not hyper data efficient but is readable and compatible
• A fixed-width text file 3 main rules?

  
  

  Row has one record with one or more columns

  Each column must have a specified width, pad character, and alignment

  Column width is consistent for all rows
• Fixed-width text files are very lightweight as it is just plaintext
• JSON is a text-based file format , that uses structured data and uses javascript object syntax
• Javascript objects can be made into json and vice versa making it an efficent way to transfer javascript
• JSON conversion to javascript is used for webpages as javascript can be used for a webpage and therefore each webpage object must be converted to json from the server and then reconverted back into the object on the users device
• XML stores and transports data
• XML is a format like html that can be used as an input format
• XML is standardised to ensure interoperability, allowing it to be understood across numerous devices and by people
• XML doesn't carry info about how the data is displayed
• XML is just plaintext data, and is therefore used for compatability between software
• Most XML files are converted into a spreadsheet, however sometimes it is used for other purposes like electronic forms
• File based structures are good for smaller amounts of data
• In file based structures all data is stored in a single directory and is generally made of packages that carry out functions for the end user
• What is the main negative of directory based data systems?

  Takes longer to create
• Why is ASCII so useful?

  It is widely used
• XML and HTML are similar in their use of tags
• XMl is more flexible in data structure but JSON produces smaller file sizes
• A collision in a directory based structure is when two or more items are given the same name
• Collisions are often found in larger datasets
• Directory based structures are inefficient as the index (which stores the location off data), increases overall size
• It is quicker to search for a record in a directory based structure
• Because directory-based data structures store metadata the user has more organisation for less space.

  THis means it is SCALABLE