In IDMS database design, what is an OOK Rec and when is it used?

Introduction / Context:
This question relates to CA IDMS network database terminology. Unlike relational databases, IDMS uses records and sets to express relationships. An OOK Rec, or one of a kind record set, is a specialized structure used in some IDMS designs. Understanding what an OOK Rec is helps you read existing IDMS data models and navigate database relationships correctly in both design and maintenance tasks.

Given Data / Assumptions:

• We are working in an IDMS database that uses CODASYL style records and sets.
• The term OOK Rec appears in design documents or interview questions.
• The question asks for the meaning and basic purpose of this structure.
• We are not dealing with backup, disaster recovery, or external temporary files.

Concept / Approach:
The phrase one of a kind record set suggests that this set has exactly one member occurrence used as a bridge to another record set. In IDMS literature, an OOK Rec is described as a one of a kind record set that helps you reach another record set. It often appears in designs that need an extra level of indirection or a single control record to access a collection of other records. The correct option must align with this database navigation purpose rather than external storage or backup scenarios.

Step-by-Step Solution:
Step 1: Focus on keywords one of a kind and record set, which clearly suggest an IDMS structural concept. Step 2: Look for the option that mentions using this one of a kind record set to access another record set. Step 3: Eliminate options that talk about work files, backups, or disaster recovery, since these are not record sets. Step 4: Also eliminate any option that mislabels OOK Rec as a junction record with many occurrences, because the name implies uniqueness. Step 5: Confirm that the remaining option matches typical IDMS interview answers and documentation about OOK Rec.

Verification / Alternative check:
You can double check by recalling common IDMS interview references, which define OOK Rec as one of a kind record set used to get to another record set. This phrasing appears consistently across IDMS question banks. No authoritative source treats OOK Rec as a backup area or a sort file. Therefore the option that describes it as a structural link between record sets is the only one that fits known definitions.

Why Other Options Are Wrong:
Option b: A temporary work file for batch sorting is not a record set inside IDMS and does not match the OOK Rec concept.
Option c: A junction record usually represents a many to many relationship and may have many occurrences, which conflicts with the one of a kind idea in the OOK Rec name.
Option d: A backup copy of an area for disaster recovery is an operational concept and not a record set used for navigation.

Common Pitfalls:
A common mistake is to confuse various IDMS structural terms such as junction records, OOK Rec, and regular member sets. Another pitfall is to interpret OOK Rec literally as any unique record rather than as a named structure in the schema. Always remember that OOK Rec is documented specifically as a one of a kind record set that helps you reach another record set in an IDMS database design.

Final Answer:
A one of a kind record set that is used to reach or access another related record set in the database structure.