Query By Example (QBE) — Capabilities and Limitations Which statement about QBE (Query By Example) is accurate in practice?

Introduction:
QBE (Query By Example) lets users compose database queries through a tabular or form-based interface instead of writing query text. This question separates realistic capabilities of QBE from common misconceptions and exaggerations.

Given Data / Assumptions:

• QBE is often implemented in tools like Microsoft Access and some ER/BI tools.
• It is meant to simplify query creation for users and analysts.
• QBE is not a complete application framework.

Concept / Approach:
We look for the statement that accurately positions QBE as a visual query builder, not an application development platform, and not a universal standard with guaranteed performance advantages.

Step-by-Step Solution:
1) Eliminate claims of a universal standard—no single cross-vendor QBE standard exists.2) Eliminate the claim that QBE cannot be used with client/server; it can be used to drive client/server queries.3) Eliminate the statement denying a visual environment; visualization is QBE’s core feature.4) Select the statement acknowledging QBE as a visual query tool, not a full app platform, and not inherently faster than SQL.

Verification / Alternative check:
Tools expose QBE-like designers that generate SQL under the hood; full applications still require UI, logic, and deployment frameworks beyond QBE.

Why Other Options Are Wrong:

• Official universal standard: No such global standard.
• Cannot be used for client/server: Incorrect; QBE-generated queries can target client/server DBMSs.
• No visual environment: Contradicts QBE’s essence.
• Guaranteed performance: Performance depends on the resulting SQL and database design, not the query builder UI.

Common Pitfalls:
Assuming a visual tool replaces knowledge of schemas or indexing; understanding data structures still matters for effective queries.

Final Answer:
QBE is a visual approach to constructing queries; complete end-to-end applications are not generally built using QBE alone.