An indexed (indexed-sequential) file offers the random-access capability of which file type and the access method characteristics of which other type?

Introduction / Context:Classical file organizations balance ease of sequential processing with the need to locate specific records quickly. Indexed-sequential files (often called ISAM-style) combine two desirable properties: direct/random access via an index and efficient sequential processing over a key order.

Given Data / Assumptions:

• Records are stored in key order with an accompanying index.
• Users may need both sequential reports and fast point lookups/updates.
• Storage is on disk, allowing non-linear access.

Concept / Approach:The index (primary plus possibly secondary) enables random access similar to a direct (random) file. Once positioned, the organization still supports efficient sequential scans—much like a sequential file—because data blocks are ordered by key. Hence, an indexed file offers the facility of a random file and the access method of a sequential file.

Step-by-Step Solution:

Verification / Alternative check:Consider typical operations: monthly statements (sequential pass) and customer inquiry by account number (random access). Indexed-sequential supports both without reorganization.

Why Other Options Are Wrong:

Common Pitfalls:Confusing indexed-sequential with pure hashed files; hashing optimizes equality lookups but undermines ordered sequential reporting.

Final Answer:Sequential file (sequential access method).