While the relationships among CA IDMS/DB record types are similar in concept to those among Total files, these relationships are defined and maintained differently. Under CA IDMS/DB, a one-to-many relationship between two or more record types is expressed by a set structure. A set structure is defined and maintained apart from the record definitions.
Set is Defined for Each Relationship
For each relationship between two or more CA IDMS/DB record types, a set is defined. One record type is designated as the owner of the set and the other record type(s) is designated as the member. A given set occurrence consists of one occurrence of the owner record type and any number of occurrences of the member record type(s).
Owner and Members are Linked by Pointers
The owner and members of a set are linked by the pointers maintained in the record prefixes. The record prefix always contains a pointer linking the record to the next record in the set, and can contain pointers linking the record to the prior, last, and/or owner record in the set.
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