Data storage is a method of operating a computer system having memory for storing and retrieving information concerning a subject, which comprises the following.
(a) in the computer system memory, storing subject data concerning a plurality of subjects wherein said data includes descriptive phrases regarding various matters with which said subjects are concerned and wherein said data includes identifying information for identifying the subjects associated with said descriptive phrases;
(b) assigning selected designation numbers to said descriptive phrases and storing said selected designation numbers in the computer system memory in association with the corresponding descriptive phrases and with the identifying information wherein said designation numbers correspond to a respective plurality of topics;
(c) in the computer system memory, storing a plurality of topic headings with each heading being designated to include a specified range of designation numbers;
(d) in the computer system, for each designation number assigned to a descriptive phrase, determining which of said topic heading range includes said designation number and storing that designation number and corresponding descriptive phrase in association with the associated topic heading;
(e) searching the computer system memory for one of the phrase descriptive of a selected matter of interest, a range of designation numbers, and a designation number, and if a descriptive phrase is identified, determining the designation number;
(f) using one of said range and designation number determined in step (e) to retrieve from the computer system memory the corresponding identifying information concerning the associated subject.
Primary Storage
Primary storage relates to semiconductor memory chips and is used to store the data and programmes currently in use. In some data processing, all instructions and data are entered in primary storage by which the computer completes its processing for results to be presented. Each storage element of memory is directly accessible which can be examined and modified without affecting other cells. Thus primary memory is also called Random Access Memory (RAM). In some applications, computer’s primary storage capabilities are insufficient and unable to handle the instructions and data needed for processing. Primary storage has volatile memory for which it is desirable to save the results of processing.
Secondary Storage
Secondary storage is the nonvolatile memory that is stored externally to the computer. Three secondary storage media used with all sizes of computer are magnetic tapes, magnetic disks and optical technology. Through secondary storage, large volume of information can be conveniently stored for future retrieval. The two types of secondary memory available are serial access memory and random access memory. It is helpful to understand in terms of a cassette tape to provide serial access memory and L.P. record to provide random access memory.
Data Warehouse for Storage
A data warehouse is a computer system designed for analyzing the historical data of an organisation, such as sales, salaries, or other information from day-to-day operations. Normally, an organization summarizes and copies information from its operational systems (such as human resources) to the data warehouse on a regular schedule, such as every night or every weekend; after that, management can perform complex queries and analysis on the information without slowing down the operational systems.
The data warehouse also normally stores information at a coarser grain than the operational systems: for example, if the operational systems contain a record for every sale, the data warehouse might simply contain the total number of sales for each product at each store. The data warehouse need not be a relational database, as it must be organised to hold information in a structure that best supports not only query and reporting, but also advanced analysis techniques, like data mining. Most data warehouses hold information for at least one year and sometimes can reach half century, depending on the business/operations data retention requirement. As a result these databases can become very large.