What the data for this category looks like
Railway operations service inquiry data mainly comes from 12306 official announcements, station operation manuals, train schedules, ticket rule documents, real-time delay notifications, and lost and found records. Data update rhythms fall into three categories: real-time updates for delay and ticket change information, daily updates for train schedules, and periodic updates for new service regulations and policy documents. Document structures include structured entries (such as train number, departure and arrival stations, ticket price) and unstructured text (such as announcement explanations and emergency guides). Fields include train number, time, station, service phone number, ticket price information in yuan, and some documents contain multilingual translation content.
What constraints these characteristics impose on knowledge base retrieval and recall
Structured schedule and ticket data require the retrieval system to support both exact matching and semantic matching, to prevent recall failures caused by input errors in train numbers. Real-time delay notifications require an incremental update mechanism, to avoid delays caused by full re-indexing. Documents of varying lengths (short entry schedules and long-text announcements) require adaptive chunking strategies, to avoid over-splitting long texts or losing context for short entries. Standardized fields and terms require the retrieval system to recognize synonymous expressions, such as "delay" and "late", while preventing irrelevant terms from appearing in recall results.
How to configure the settings
| Configuration Item | Suggested Setting | Rationale |
|---|---|---|
similarity | 0.72–0.78 | Fits the standardized query scenario for railway inquiries. A threshold that is too low will include irrelevant content, while a threshold that is too high will miss synonymous expressions. This aligns with the parameter logic of FastGPT v4.17.0 |
limit | Top 6 entries | Maximum of 6 results per recall, matches the common question coverage range for railway inquiries, and prevents context from exceeding the model's processing limit |
searchMode | Hybrid retrieval | Combines semantic matching and exact matching, adapts to mixed data sources of structured train data and unstructured announcement documents |
usingReRank | Enabled | Performs secondary ranking on recall results, optimizes the display priority of long-text announcements and short-entry schedules |
datasetSearchUsingExtensionQuery | Enabled | Performs synonymous expansion on user questions, covering common synonymous expressions such as "delay", "late", "ticket refund", and "ticket change" |
collectionIds | Bound to railway operations-specific dataset ID | Only retrieves uploaded railway ticketing, service, and emergency documents, preventing irrelevant business data from being included |
Three common misconfigurations
- Symptom: Knowledge base file citations are still returned when searching for questions with no matching content. Cause: No empty result fallback logic is configured, or the unnecessary generative fallback switch is not turned off.
- Symptom: Some field data in uploaded structured table datasets is missing. Cause: Table column names were not aligned with railway operation standard fields (such as train number, arrival station) in advance, or the option to retain the original data structure was not checked during upload.
- Symptom: Tool calls and knowledge base retrieval cannot take effect at the same time. Cause: The knowledge base retrieval node and tool call node were not configured in sequence in the tool flow, or the priority of trigger conditions was not set correctly.
How to confirm the configuration is correct
- Submit the test question "Is Train G123 delayed today?" and check if the real-time information document for the corresponding train is included in the recall results.
- Submit a question with no matching content: "Is there any mysterious train from Beijing to Shanghai tomorrow?" and check if an empty result or a clear prompt that no relevant information was found is returned.
- Upload a new railway ticketing rule document, wait 10 minutes, then retrieve the corresponding clause, and confirm that the new data has been recalled.
- View the retrieval log and confirm that the number of recall results does not exceed the set
limitvalue.
The values provided here are common starting points and should be evaluated against the reader's own samples.
Question material comes from public community discussions. Configuration values are common starting points and should be measured against your own samples. Verified on 2026-09-28.