What the data for this category looks like
Service inquiry data for infrastructure construction is primarily sourced from construction logs, bidding documents, completion acceptance reports, industry construction specifications, and project ledgers. Data update schedules fall into three categories: construction-related documents are updated daily as projects progress, bidding and acceptance documents are updated immediately upon milestone completion, and industry specifications are synced annually or quarterly. Individual documents typically include fields such as project number, construction area, compliance clauses, and acceptance standards. Units use engineering-specific measurement standards such as meters, cubic meters, and workdays. Some documents include attachments such as drawings and test reports.
What constraints these characteristics impose on the knowledge base retrieval and recall link
The multiple document types and update rhythms for infrastructure construction create multiple constraints for retrieval and recall. Construction documents are updated daily and contain large volumes of real-time data, so retrieval must support incremental synchronization to avoid performance losses from full re-scans. There are many engineering-specific terms, and a need for precise field matching. Retrieval must balance semantic search and precise field recall. Some documents include non-text attachments such as drawings and test reports, so a retrieval pipeline that supports multimodal content must be configured. Long documents account for a large share of the dataset, with individual documents potentially containing tens of thousands of characters. Chunk granularity must be controlled appropriately to retain contextual connections.
How to configure settings
Reference only; verify against the target FastGPT release and deployment documentation.
| Configuration Item | Recommended Setting | Rationale |
|---|---|---|
similarity | 0.75–0.85 | Semantic similarity threshold for matching engineering terminology, covers semantic associations of specialized vocabulary while filtering irrelevant results |
limit | Top 10 | Limits the number of single retrieval results, aligns with the effective information boundary of a single query in engineering consultations |
searchMode | hybrid | Combines semantic retrieval and precise field retrieval, matches precise fields such as project number and construction area while covering semantic queries |
usingReRank | Enabled | Re-ranks retrieval results to optimize the ranking priority of results related to engineering terms |
datasetSearchUsingExtensionQuery | Enabled | Automatically expands synonymous queries for engineering terminology, improves recall rate across term searches |
collectionIds | Configured by project group | Restricts retrieval scope to the knowledge base set for the corresponding project, avoids interference from cross-project data |
Three common mistakes
- Symptom: Image retrieval results for knowledge bases created via localFile display expiration prompts and fail to load properly. Cause: No permanent image storage policy is configured. The default generated temporary links have an expiration date, and image resources were not synced to a dedicated storage node.
- Symptom: The number of retrieval results does not match the configured
limitparameter, with either excess or insufficient results. Cause: ThecollectionIdsparameter was not correctly associated. The retrieval scope covers multiple unrelated project knowledge bases, leading to deviations in result count. - Symptom: The retrieval recall rate for engineering specialized terminology is low, and documents with synonymous expressions cannot be matched. Cause: The
datasetSearchUsingExtensionQueryconfiguration was not enabled. Automatic expansion of synonymous queries for specialized terminology was not performed, leading to failure to hit some terms.
How to confirm the configuration is complete
- Upload a project construction log document, search for content containing the specified project number, and verify that the retrieval results include the precise fields from this document.
- Enter an engineering specialized term such as "steel binding specification", and verify that the retrieval results cover documents with related synonymous expressions.
- Check the number of retrieval return results, confirm that it matches the value of the configured
limitparameter. - Check the loading status of multimodal attachments, confirm that content such as drawings and test reports can be displayed normally.
The values provided are common starting points and should be measured 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.