File organization terminology: A file that maintains multiple indexes (access paths) to the same data set is commonly called what?

Introduction / Context:
File organizations differ in how they enable access to stored records. When fast retrieval by many different keys is needed, systems add multiple indexes. The term “inverted file” describes a structure that inverts from values to lists of record identifiers across multiple keys.

Given Data / Assumptions:

• We need a file that supports several distinct indexes.
• Use cases include search by author, subject, customer, or product across the same records.
• Terminology is from classical file and IR (information retrieval) systems.

Concept / Approach:
An inverted file maintains, for each key value, a posting list of record pointers where that value appears. Multiple inverted lists can coexist for different fields, enabling fast lookups and Boolean combinations. This is the basis of many search engines and library catalogs. An indexed-sequential file typically has one primary sequential order with a single index; a plain indexed file may not imply multiple secondary indexes; a sequential file has no indexes at all.

Step-by-Step Solution:

Verification / Alternative check:
Information retrieval literature and database textbooks use the term “inverted index” for multi-key retrieval, confirming the choice.

Why Other Options Are Wrong:

• Sequential: linear scans only.
• Indexed: ambiguous, not necessarily multi-index.
• Indexed-sequential: usually one main index over a sequential file.

Common Pitfalls:
Confusing “indexed-sequential” with “many indexes”; it focuses on maintaining sequential order with a primary index, not numerous secondary keys.

Final Answer:
Inverted file