Difficulty: Easy
Correct Answer: when inquiries about accounts payable must be answered online
Explanation:
Introduction / Context:
Choosing the right storage organization for files in an accounting system affects responsiveness and cost. Direct access storage devices (DASD)—a term historically referring to disks—support rapid random access to individual records. Outstanding (open) invoices are frequently queried by vendors, approvers, and finance staff, so access characteristics matter for service levels and productivity.
Given Data / Assumptions:
Concept / Approach:
Use DASD when workloads emphasize direct, keyed retrieval. Online inquiry screens call up a small set of invoices out of a large file, which is best served by random access structures (e.g., indexed files, database tables on disk/SSD). Batch payment processing often processes a scheduled set sequentially, which could run efficiently even on sequential storage. A design requirement like “last record points to first” indicates a circular list and is not a valid criterion for choosing DASD by itself.
Step-by-Step Solution:
Verification / Alternative check:
File organization principles and DBMS indexing guidelines recommend random-access storage for high-selectivity, user-driven queries, confirming this choice.
Why Other Options Are Wrong:
Common Pitfalls:
Assuming online write implies online read patterns; design storage for the dominant access pattern, which for open invoices is often inquiry-heavy.
Final Answer:
when inquiries about accounts payable must be answered online
Discussion & Comments