Direct Access

Direct access is when data is accessed without accessing previous data items, such as when we go directly to a track we want on a CD and skip all of the preceding tracks. Data is stored at a particular storage location based on a mathematical procedure or algorithm. Direct access then uses this algorithm to calculate the approximate location of the data. Often this location is fixed using an index stored at the start of a ROM disk or in the first sector pof a hard drive. When an index is used it is called indexed access. Indexed access requires additional processing time to search the index to find the exact location and to maintain the index.

 

 

Related Topics (Information Systems) : DBMS, The 5 Types of Information Systems, Expert Systems, TPS, DSS, ES, MIS, OAS, Characteristics, computerised methods, non-computerised methods, flat file databases, relational databases, data modelling, URLs, storyboards, searching, HTML, backups, security methods, encryption, firewalls, virus' and virus scanners, passwords and security levels, social and ethical issues, data accuracy, data integrity, data validation, data bias, data reliability, privacy, ownership and control of data, access to data, data warehousing, data mining, freedom of information, acknowledgement of data sources, issues related to new trends, sequential access, direct access, distributed databases, storage media, querying, operators, wildcards, sorting, SQL, biometrics and ethical issues, face recognition

 

See Also: Knowledge Management, data mining,Information systems