Data association

Data held in a computer file are divided into records (also called entities or nodes), each consisting of a contiguous string of data divided into fields. In order to associate a record with other records (or fields), a logical system must be used to achieve this linkage. Several techniques of data association exist, including chains and pointers, and directories. Chains are used logically, not physically, to link records together based on commonalities and functional interrelationships. A pointer represents the address (reference point) of a particular record. The chaining operation is achieved by using pointers to directly or indirectly associate one record in the chain to the next record in the chain. The need for chaining arises when information is stored in a sequence other than the one that facilitates the type of retrieval desired.