Exchanging Data

• Relational Data bases:

  an entity (item) of interest where the information is stored. relational data bases are able to recognise the difference between entities and create different tables for these entities
• flat file data base consist of only one file based around a single entity and its attributes
• Primary key is a unique identifier for each record in the table
• Foreign key is the attribute that links two tables together
• Secondary Key allows a database to be searched quickly
• there are different degrees of relationships two data bases can have

  1. One-to-One: Each entity can only link to one other entity
  2. One-to-Many: one table can link to many other tables
  3. Many-to-Many: one entity can link to many entities
• Capturing data:

  1. Manually entering
  2. MICR
  3. OCR
  4. OMR
• Selecting and Managing data:

  selecting the correct data is an important part of data pre-processing
• Exchanging data the process of transferring the collected data