2. What is Data? Data is any fact or statistic which can be operated on to derive meaningful information. It is a raw fact. Simply put: Data is any raw fact Eg: Size = 12 is data Name = ‘Dennis’ is another data We cannot derive conclusions directly from the data without processing them Example of a Data
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4. For example, if Jenny wants to buy a laptop, she needs the right data to make appropriate decision on the model. Like its cost, market value, etc.
5. Hence, every decision depends on the data corresponding to it WHICH SHALL I BUY? Cost = $360 Cost = $450
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7. All aspects of the modern business and domestic life-styles feed of huge amounts of data
8. The Amount of data is increasing exponentially and we needed a flexible, reliable and secure way to organize this data.
14. What is so special about a database? Why can’t we just use files? (like text files and word documents). The Next slide answers this Qn.
15. Problems with files Inconsistency In a system, a user may use different applications and these may use different formats of data. Hence, interoperability between their data is difficult For Example: Willy, Tim and Rose have been asked to write an essay on MJ, and they use different platforms, they’d have difficulty combining the Data into a single-final document: Incompatibilty X Willy Uses MicrosoftWord Tim Uses WordStar Rose Uses Mellel, a Word processor for Macintosh systems
16. Problems with files Data Redundancy When handling large amount of data, there might be recurrences of data in case of files. This wastes memory space. Integrity The data is susceptible to corruption due to system failures Concurrent Access anomalies When many people try to write a piece of data concurrently – we’ll have problems in case of files Security problem Ill minded people may get access to our files if they are not secured properly.
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18. In Prisons for managing info about the prisoners
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20. Database Features Example Consider a database for the dreams that ‘George’ had this week. It has a table called ‘History’ where he stores the date and time at which he dreamt. This table will look as follows: An ‘ATTRIBUTE’ which can uniquely identify a record in a table is called a ‘KEY’. Eg: Dream Number The ‘TYPE’ of data is called as ‘ATTRIBUTE’ or ‘FIELD’. Eg: Date, Time,etc The ‘VALUES’ of a set of attributes, which define a unique object is a ‘RECORD’
27. A Table consists of: Records (Rows in a table) Attributes (Columns in a table) Keys (Used to uniquely identify a record in a table) End
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