As you previously heard, databases are the staple of business computing. Originally, that is pre 1970 information electronically was stored in flat files. This means that data was maintained in one long text file called a tab delimited file, a means of separating the fields in a record. Each entry in the tab delimited file is separated by a special character such as a vertical bar. Each entry contains a multiple pieces of information fields about a particular object or person that are grouped together as a record. The text file makes it difficult to search for specific information or to create reports that include only certain fields from each record.

Let us look at an example of a multinational operation of their personnel file that contains records of thousands of employees. You can see that we would have to search sequentially through the entire file together related information, such as a name or a monthly salary. And there are a number of other problems associated with this flat flat file. Let me run through just a few scenarios. If you wanted to search for a specific name, and it was at say, the end of the file, you would have to sequentially go through every record in the file before you reach the end of the file, which would take an enormous amount of time. See also you want to make a change to a particular record in the file.

Again, you would have to search for this particular record by sequentially going through each one of the files, or even a deletion would require the same sequential steps. Now if you have only three records as what appears in the files seen on the screen, perhaps you could do this quickly or even by hand. But if you had to search this electronically, it would take an immense amount of resources and time to find each one of the records that you are searching. This problem is not trivial, and represents a serious logistic problem. Researchers sought the answers that is again prior to 1970. The solution was derived by EF COD through a mathematical algorithm.

Briefly, he created a relational model of data. relational databases use tables to store information. The standard fields and records are represented as columns, a fields and rows IE records in a table. With a relational database you can quickly compare information because the arrangement of data in columns the relational data model takes advantage of this uniformity to build complete new tables are required information from a week from existing tables. In other words, it uses the relationships of similar data to increase the speed and versatility of the database. So why do we use this complicated term the relational part of the name actually comes from the mathematics that solved the problem of flat files.

The theory that caught propose was steeped in relational algebra, and relational calculus. Fortunately, we will avoid the math part and concentrate it and concentrate on the business practical aspects of relational databases. A typical relational database has somewhere between 10 to more than 1000 tables. Each table contains a column or columns that other tables can key in on together information from that table. by storing this information in separate tables, the database can create a single small table with the locations that then can be used for a variety of purposes by other tables in the database. Typical large database such as the one used by Amazon would have hundreds or thousands of tables, all used together to quickly find the exact information needed at a given time.

Other solutions have been presented, including hierarchical network and object oriented databases, but by far cots relational database model is the most popular